What is the function of a crypto map on a PIX Firewall?

A.
To define the policy that will be applied to the traffic.

B.
To specify which algorithms will be used with the selected security protocol.

C.
To configure a pre-shared authentication key and associate the key with an IPSec peer address or host name.

D.
To map transforms to transform sets.

Explanation:

Crypto map entries must be created for IPSec to set up SAs for traffic flows that must be encrypted.
Reference: Cisco Secure PIX Firewalls (Ciscopress) Page 215