The surface area of a sphere is same as the curved surface area of a right circular cylinder whose height and diameter are 12 cm each. The radius of the sphere is
Choose the correct choice
A) 3 cm B) 4 cm C) 6 cm D) 8 cm E) none

Rationale: "solution 4 π r 2 = 2 π 6 x 12 ⇒ r 2 = ( 6 x 12 / 2 ) ⇒ 36 ⇒ r = 6 cm . answer c"
Answer: C