In a DoD model, also known as a TCP/IP model, a TCP or UDP header is added to a message at
different layers. Which of the following information is added to the source and destination port
fields of the TCP header?

A.
Hardware addresses of the source and destination hosts

B.
Source and destination port numbers identifying the upper layer protocol

C.
Software addresses of the local and remote hosts

D.
Source and destination port numbers identifying the transport protocol