What is required to scan both UDP and TCP ports?

• A. -sU
• B. -p
• C. -sU with at least one TCP scan type such as -sS, -sF, or -sT
• D. -sT

Answer: (C)

The main idea is that UDP and TCP scans are controlled by different switches, so to cover both you must enable UDP scanning and also pick a TCP scan method in the same command. UDP scanning uses a switch like -sU, which targets UDP ports, but to scan TCP ports you need a TCP scan type such as -sS (SYN), -sF (FIN), or -sT (connect). The only option that combines both is to use -sU together with at least one TCP scan type in the same run. For example, using -sU -sS target will inspect both UDP and TCP ports. The other options fail to scan one of the protocols: -sU alone scans only UDP, a plain -sT covers TCP only, and -p is just for port ranges, not for selecting protocols.