A Security Parameter Index (SPI) and the identity of the security protocol
(AH or ESP) are the components of:

A.
SSL

B.
IPSec

C.
S-HTTP

D.
SSH-2

Explanation:
The correct answer is IPSec. The SPI, AH and/or ESP and the destination
IP address are components of an IPSec Security Association (SA.)
The other answers describe protocols other than IPSec.