Which of the following operating systems are capable of multiprocessing? (Choose all that apply)

A.
Windows XP

B.
Windows NT

C.
UNIX

D.
OS/2

Explanation:
In a multiprocessing system, the operating system is responsible for allocating resources to competing processes in a controlled environment. Most modern network operating systems are capable of this function, including Windows NT, Windows 2000, Windows XP, UNIX and IBM’s OS/2.
References:
Charles J. Brooks, Server+ Certification Exam Cram 2 (Exam SK0-002), QUE Publishing, Indianapolis, 2006, pp. 62-64.