First post

So I'm scheduled to take the exam on Feb 19th. I'm competely nervous and have been cramming a ton of material, btw thanks ISC2 for changing exam scope the month I'm supposed to take it. I've been running into a reoccuring problem while taking practice tests and would much appreciate any advice input available.
Should I be answering questions based on common sense or should I focus on what's in the book (Shon Harris 5th ed.). I've been taking some practice tests where the book answer isnt the "Best" answer. Ushually I go common sense first but it's easy to switch gears when something in the back of your head says, "wait the book said this".
Example: (Rephrased Question)
What is the best method to limit unauthorized access to critical servers though a wireless access point?
A) Rule Based Access Contol

Discretionary Access Control
C) WPA2 Enterprise
D) 802.11n
My brain says WPA2 enterprise because that's what you use. But, Rule Based kinda covers that and much more. It certainly doesnt help your torn between a technical implementation and a theory.
Based on answers to the questions I've practiced the answer is WPA2 Enterpise. But as a template for the exam should I place my judgement above the book?