Which S3 Storage Class Meets Rare Access with Immediate Retrieval?

Why the Answer Is Correct

S3 Standard-IA is engineered for exactly the pattern in the scenario: data that is accessed infrequently but must remain available with millisecond latency. Its per-GB storage price is lower than S3 Standard, and the class charges a retrieval fee only when objects are read, keeping total cost low for rarely accessed audio files. Because each file is 5 MB, it far exceeds the 128 KB minimum billable object size for Standard-IA, so there is no small-object billing penalty. No other class in the list combines immediate retrieval with a lower storage cost than S3 Standard for this access pattern.

Why the Other Options Are Wrong

S3 Standard (A) provides immediate retrieval but carries a higher per-GB storage price than Standard-IA, so it is not the most cost-effective choice for files that are rarely accessed. S3 Glacier Flexible Retrieval (C) and S3 Glacier Deep Archive (D) are archive storage classes; both are cheaper to store data in, but neither can retrieve objects immediately—Flexible Retrieval takes minutes to hours, and Deep Archive takes hours. A learner comment cited lower Glacier storage prices, but cost per GB alone is irrelevant when the retrieval-latency requirement eliminates those classes. The question's phrase "must be able to retrieve the files immediately" directly disqualifies both Glacier options.

Community Comment Notes

ShaiTay captured the deciding logic, noting that S3 Standard-IA is "rarely accessed, but needs to be retrieved immediately." BlueMan93 also ruled out Glacier because it is "designed for archiving data that doesn't require immediate access." CharmaineBowman compared monthly storage costs and leaned toward Glacier Flexible Retrieval, but that comparison omitted the retrieval-latency requirement the question explicitly imposes. a77c459 kept it simple with "B looks right answer," reflecting the clear consensus.