How can Company B reduce the number of empty responses?

Company B provides an online image recognition service and utilizes SOS to decouple
system components for scalability The SQS consumers poll the imaging queue as often as
possible to keep end-to-end throughput as high as possible. However, Company B is
realizing that polling in tight loops is burning CPU cycles and increasing costs with empty
responses. How can Company B reduce the number of empty responses?

A.
Set the imaging queue visibility Timeout attribute to 20 seconds

B.
Set the DelaySeconds parameter of a message to 20 seconds

C.
Set the Imaging queue ReceiveMessageWaitTimeSeconds attribute to 20 seconds

D.
Set the imaging queue MessageRetentionPeriod attribute to 20 seconds