The lateral surface area of frustum of a right circular cone,if the area of its base is $$16 \pi  cm^2$$ and the diameter of circular upper surface is 4 cm and slant height 6 cm, will be

A

$$30 \pi  cm^2$$

B

$$48 \pi  cm^2$$

C

$$36 \pi  cm^2$$

D

$$60 \pi  cm^2$$