Which of the following 802.11 standards can operate at both 2.4 GHz and 5.0 GHz?

Which of the following 802.11 standards can operate at both 2.4 GHz and 5.0 GHz?

A.
A

B.
B

C.
G

D.
N

Explanation:

http://en.wikipedia.org/wiki/IEEE_802.11(see 802.11n)