How to centralize CloudWatch metrics and alarms across accounts and Regions?

Why the Answer Is Correct

CloudWatch cross-account observability is purpose-built for this scenario: the operations team's account is designated the monitoring account, each application account is onboarded as a source account, and the monitoring account can then build a single dashboard in one Region that queries metrics, alarm states, and even Logs Insights from all linked accounts and Regions. Because the source accounts are only linked — not modified with roles, functions, or forwarding pipelines — the operations team gains read access without duplicating data or adding per-account plumbing. Option D matches every requirement: one Region, one dashboard, metrics and alarms from all applications, across accounts and Regions.

Why the Other Options Are Wrong

Option A relies on the older cross-account cross-Region console behavior, which is enabled in the account where the dashboard is created (the monitoring account) and depends on a sharing role in the source accounts, so "enable in each application account" is the wrong direction and does not deliver a truly unified cross-Region view. Option B only forwards alarm state changes into an SNS topic; it delivers notifications, not the CPU utilization and request latency metric data a dashboard needs to render graphs. Option C works only in the sense of brute force — Lambda functions polling and re-publishing metrics into the operations account duplicate data, add cost and lag, and cannot faithfully reproduce alarm states or original metric dimensions.

Community Comment Notes

Bad_Mat states plainly that "The correct answer option is D" and walks through the monitoring-account/source-account designation followed by dashboard creation in the operations account, which mirrors the official feature design. That reasoning also implicitly rejects the per-application-account console setup in option A, since the link is created once in the monitoring account. No comment endorses the EventBridge or Lambda approaches, so the community view is aligned with the vendor's documented cross-account observability workflow.