The surface area of a sphere is same as the curved surface area of a right circular cylinder whose height and diameter are 14 cm each. The radius of the sphere is  Select the correct option:
A) 3 cm
B) 4 cm
C) 6 cm
D) 7 cm
E) none

Rationale: "solution 4 î r 2 = 2 î 7 x 14 â ‡ ’ r 2 = ( 7 x 14 / 2 ) â ‡ ’ 49 â ‡ ’ r = 7 cm . answer d"
Answer: D