The sizes of source and destination port address in TCP header are ___________ respectively.

A. 16-bits and 32-bits

B. 16-bits and 16-bits

C. 32-bits and 16-bits
D. 32-bits and 32-bits

Explanation: All port addresses are of 16 bits and they specify the type of service being used by the network entity. For example, port 21 is used for FTP connections and port 25 is used for ICMP connections.

Occurrence: 0, System Administrator 2026