which configuration must be the exact reverse (mirror image) of the other IPsec peer?

When you configure a site-to-site IPsec VPN tunnel, which configuration must be the exact
reverse (mirror image) of the other IPsec peer?

A.
pre-shared key

B.
crypto ACL

C.
static route

D.
IPsec transform set

E.
ISAKMP policy

F.
crypto map