The correct choice is 10. The ReceiveMessage API for Amazon SQS uses the MaxNumberOfMessages parameter which accepts values from 1 through 10 and so a single ReceiveMessage request can return at most 10 messages. Consumers cannot pick a specific message and they only control the maximum batch size per request.

The 10 limit is consistent with SQS batch operations which also use 10 entry limits for operations that process multiple messages at once. This makes batching predictable and it is the documented hard cap for a single API call.

The option 20 is incorrect because SQS does not return 20 messages in one ReceiveMessage call and the service enforces the maximum of 10.

The option 5 is incorrect because although requesting five messages is valid it is not the maximum you can ask for and you may request up to 10.

The option 25 is incorrect because it exceeds the documented service limit and SQS will not return that many messages in a single ReceiveMessage request.

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