Which of the following command line switch would you use for OS detection in Nmap?

A.
-D

B.
-O

C.
-P

D.
-X

Explanation:
OS DETECTION: -O: Enable OS detection (try 2nd generation w/fallback to 1st) –
O2: Only use the new OS detection system (no fallback) -O1: Only use the old (1st generation) OS detection system –osscan-limit: Limit OS detection to promising targets –osscan-guess: Guess OS more aggressively