The PORT NUMBER range is

1. TCP and UDP use 16-bit port numbers, ranging from 0 to $2^{16}-1 = 65535$. 2. Conventional ranges: - 0-1023: WELL-KNOWN ports (privileged, OS-restricted). E.g. HTTP=80, HTTPS=443, FTP=21. - 1024-49151: REGISTERED ports (e.g. PostgreSQL=5432). - 49152-65535: DYNAMIC/EPHEMERAL ports (used by clients). 3. Option A is only the well-known well-known range. Option B is well-known only. Option D is a 32-bit range (not used for ports). _Source: RFC 1180 "A TCP/IP Tutorial", §7-8 (TCP + Network Applications, port numbers)._