Which physical controls can both detect and deter?

SY0-701 By islever Editorial Last updated

Short answer

AD Lighting Sensor

Question

Which of the following physical controls can be used to both detect and deter? (Choose two.)
  1. Lighting Correct Answer
  2. Fencing
  3. Signage
  4. Sensor Correct Answer
  5. Bollard

Key Takeaways

The key to answering this question correctly is understanding that only controls with active monitoring or visibility capabilities can both detect and deter - passive barriers like fencing and bollards only deter, while signage only deters without detection capability.

This CompTIA Security+ SY0-701 question explores physical security controls that serve dual purposes of detection and deterrence. Lighting and sensors are the correct answers as they both illuminate or identify unauthorized activity while discouraging potential intruders.

Common mistake: Many candidates incorrectly choose signage (C) and sensors (D), mistakenly believing that warning signs can detect intruders. Signage is purely a deterrent control with no detection capability, making this a common trap answer.

Expert Analysis

Understanding Dual-Purpose Physical Security Controls

This question tests your understanding of how physical security controls can serve multiple security functions. The correct answers are Lighting (A) and Sensor (D).

Why Lighting is Correct

Lighting serves both detection and deterrence functions effectively. From a detection standpoint, proper illumination allows security personnel and surveillance systems to identify unauthorized individuals attempting to approach under cover of darkness. From a deterrence perspective, well-lit areas eliminate the concealment that intruders rely on, making them think twice before attempting unauthorized access. The psychological impact of being visible significantly reduces the likelihood of security breaches.

Why Sensors are Correct

Sensors (including motion detectors, infrared sensors, and other monitoring devices) actively detect movement or presence in secured areas. When sensors are visible or their presence is known, they also serve as a deterrent. Potential intruders who know they will be detected are less likely to attempt unauthorized entry. Modern sensor systems often integrate with alarm systems and lighting to create layered security responses.

Why Other Options Are Incorrect

Fencing (B) is primarily a deterrent and delay control. While it physically prevents or slows unauthorized access, it has no inherent detection capability unless combined with sensors or surveillance systems.

Signage (C) is purely a deterrent control. Warning signs like "Authorized Personnel Only" or "24-Hour Surveillance" may discourage potential intruders, but they cannot detect or alert security personnel to actual breaches.

Bollards (E) are physical barriers designed to prevent vehicle access to pedestrian areas or building entrances. Like fencing, they deter and delay but cannot detect unauthorized activity.

Community Consensus

The community strongly agrees with answers A and D (93% vote), with multiple test-takers confirming that these are the only two options that possess both detection and deterrence capabilities. As one community member noted, "The only 2 who can actually detect anything" - highlighting the importance of understanding which controls have active monitoring functions.

Official Reference

https://www.compTIA.org/training/by-certification/security

This link opens the official vendor documentation in a new tab.

Exam Strategy

When encountering questions about security controls serving multiple purposes, focus on the specific functions each control performs. Create mental categories: detection-only, deterrence-only, delay-only, and dual/multi-purpose controls. This systematic approach helps eliminate incorrect options quickly.

Community Votes

AD
100%

100% of anonymous learners picked answer AD. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 4 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 4

  1. TrebleSmith 👍 9
    Lighting will illuminate the area, detect people attempting to be under the cover of night, and deter them from committing unwanted acts. Furthermore, a sensor will detect movement in an area, and sensors that are visible can ward off any potential bad actors.
  2. ETQ 👍 3
    The only 2 who can actually detect anything.
  3. Gman530 👍 2
    These are the only 2 that can both detect and deter
  4. nesquick0 👍 1
    C , D zzzz

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