Solve the Problem $\pi$ B) 16k $\pi$ C) 64k $\pi$ D) 256k $\pi$

Solve the problem.
-Find the mass of a sphere of radius 4 if k a constant.

A) 512k $\pi$
B) 16k $\pi$
C) 64k $\pi$
D) 256k $\pi$