How can the developer inspect the timing of the DynamoDB API calls?

An AWS Lambda function accesses two Amazon DynamoDB tables. A developer wants to improve the performance of the Lambda function by identifying bottlenecks in the function .

How can the developer inspect the timing of the DynamoDB API calls?
A . Add DynamoDB as an event source to the Lambda function. View the performance with Amazon CloudWatch metrics
B . Place an Application Load Balancer (ALB) in front of the two DynamoDB tables. Inspect the ALB logs
C . Limit Lambda to no more than five concurrent invocations Monitor from the Lambda console
D . Enable AWS X-Ray tracing for the function. View the traces from the X-Ray service.

Answer: A