You need to reduce the costs associated with storing the logs

You administer an Azure Storage account with a blob container. You enable Storage
account logging for read, write and delete requests. You need to reduce the costs
associated with storing the logs. What should you do?

A.
Execute Delete Blob requests over https.

B.
Create an export job for your container.

C.
Set up a retention policy.

D.
Execute Delete Blob requests over http.

Explanation:
Ref: http://blogs.msdn.com/b/windowsazurestorage/archive/2011/08/03/windows-azurestorage-logging-using-logs-to-track-storage-requests.aspx