What improvement does EAP-FASTv2 provide over EAP-FAST?

What improvement does EAP-FASTv2 provide over EAP-FAST?
A . It allows multiple credentials to be passed in a single EAP exchange.
B . It supports more secure encryption protocols.
C . It allows faster authentication by using fewer packets.
D . It addresses security vulnerabilities found in the original protocol.

Answer: A