Suppose a TCP header is encrypted at the TCP layer. Can this TCP packet be delivered to the destination without using some type of TCP gateway? When does the encrypted TCP header need to be decrypted? Select one answer that is most appropriate. Partial credits may be given.

a$.$

No$,$ it cannot. It needs a TCP gateway.

b$.$

Yes, this TCP packet can be delivered to the destination without doing anything extra, for the IP packet that encapsulates this TCP payload has a plaintext IP header.

c$.$

Only when the IP packet that contains the encrypted TCP payload reaches the destination, the encrypted TCP payload is needed to be decrypted for traffic control.

d$.$

Both b and c$.$

e$.$

None of the above.