On Intel x86 systems, the kernel normally runs in which CPU ring?

A.
Ring 0

B.
Ring 1

C.
Ring 2

D.
Ring 3

Explanation:
Answer A is correct; the kernel normally runs in ring 0, the most trusted part of the system.

Incorrect Answers and Explanations: B, C, and D: Answers B, C, and D are incorrect. Ring 1 is theoretically used for parts of the OS that do not fit in ring 0. Ring 2 is theoretically used for device drivers. Ring 3 is used for user applications.