Which of the following is MOST likely the cause of the application latency?

A Developer has an application that can upload tens of thousands of objects per second to Amazon S3 in parallel within a single AWS account. As part of new requirements, data stored in S3 must use server side encryption with AWS KMS (SSE-KMS). After creating this change, performance of the application is slower.

Which of the following is MOST likely the cause of the application latency?
A . Amazon S3 throttles the rate at which uploaded objects can be encrypted using Customer Master Keys.
B . The AWS KMS API calls limit is less than needed to achieve the desired performance.
C . The client encryption of the objects is using a poor algorithm.
D . KMS requires that an alias be used to create an independent display name that can be mapped to a CM

Answer: B