After creating a new AWS account, you use the API to request 40 on-demand EC2 instances in a single AZ.
After 20 successful requests, subsequent requests failed. What could be a reason for this issue, and how
would you resolve it?

A.
You encountered a soft limit of 20 instances per region. Submit the limit increase form and retry the failed
requests once approved.

B.
AWS allows you to provision no more than 20 instances per Availability Zone. Select a different Availability
Zone and retry the failed request.

C.
You need to use Amazon Virtual Private Cloud (VPC) in order to provision more than 20 instances in a
single Availability Zone. Simply terminate the resources already provisioned and re-launch them all in a
VPC.

D.
You encountered an API throttling situation and should try the failed requests using an exponential decay
retry algorithm.