In CEH v13 Module 03: Scanning Networks, stealth scanning refers to a method of scanning that avoids detection by not completing the TCP handshake.

-sS = TCP SYN scan (Stealth scan)

Sends SYN packet.

If SYN-ACK is returned, the port is open; then a RST is sent back instead of completing handshake.

Harder to detect via IDS/IPS.

Option Analysis:

A. -sM: TCP Maimon scan (rarely used).

B. -sU: UDP scan.

C. -sS: Stealth SYN scan.

D. -sT: TCP Connect scan (not stealthy).