During the establishment of an Easy VPN tunnel, when is XAUTH performed? 

Answer options:

A. at the end of IKEv1 Phase 2
B. at the beginning of IKEv1 Phase 1
C. at the end of Phase 1 and before Phase 2 starts in IKEv1 and IKEv2
D. at the end of Phase 1 and before Phase 2 starts in IKEv1

D