Which Nmap scan is does not completely open a TCP connection?

Q. Which Nmap scan is does not completely open a TCP connection?
A. SYN stealth scan
B. TCP connect
C. XMAS tree scan
D. ACK scan
Answer: SYN stealth scan

A. SYN stealth scan
B. TCP connect
C. XMAS tree scan
D. ACK scan
Answer: SYN stealth scan