By default, temporary security credentials for an IAM user are valid for a maximum of 12 hours,
but you can request a duration as long as ______ hours.

A.
24

B.
36

C.
10

D.
48

Explanation:
By default, temporary security credentials for an IAM user are valid for a maximum of 12 hours,
but you can request a duration as short as 15 minutes or as long as 36 hours.
http://docs.aws.amazon.com/STS/latest/UsingSTS/CreatingSessionTokens.html