What mode of ESP does Jacob need to use to encrypt the IP traffic?

The agency Jacob works for stores and transmits vast amounts of sensitive government data that cannot be compromised. Jacob has implemented Encapsulating Security Payload (ESP) to encrypt IP traffic. Jacob wants to encrypt the IP traffic by inserting the ESP header in the IP datagram before the transport layer protocol header.

What mode of ESP does Jacob need to use to encrypt the IP traffic?
A . He should use ESP in transport mode.
B . Jacob should utilize ESP in tunnel mode.
C . Jacob should use ESP in pass-through mode.
D . He should use ESP in gateway mode

Answer: B