The edge of a cube is 3a cm. Find its surface? Select:
A) 24 a 8	B) 24 a 4	C) 24 a 1	D) 54 a 2	E) 24 a 7

Rationale: "6 a 2 = 6 * 3 a * 3 a = 54 a 2 answer : d"
Answer: D