How would you know when a cable is reversed?

A.
When the cable has two individual wires wrapped in a foil shielding.

B.
When the colors appear in the opposite order.

C.
When the colors appear in identical order on both plugs.

D.
None of the above.

Explanation:
Determining which type is being used is easily accomplished by aligning the ends of the cable side by side. With the contacts facing you, compare the colors from left to right. If the colors appear in identical order on both plugs, the cable is straight-through. If the colors appear in the opposite order, the cable is reversed.
References:
Charles J. Brooks, Server+ Certification Exam Cram 2 (Exam SK0-002), QUE Publishing, Indianapolis, 2006, pp. 227-240.