If you check the box "Use Aggressive Mode", in the IKE Properties dialog box:

A.
The standard three-packet IKE Phase 1 exchange is replaced by a six-packet exchange.

B.
The standard six-packet IKE Phase 2 exchange is replaced by a three-packet exchange.

C.
The standard three-packet IKE Phase 2 exchange is replaced by a six-packet exchange.

D.
The standard six-packet IKE Phase 1 exchange is replaced by a three-packet exchange.

E.
The standard six-packet IKE Phase 1 exchange is replaced by a twelve-packet exchange.