Two Planets Have the Same Free-Fall Acceleration on the Surface,but $\sqrt { 2 }$

Multiple Choice

Two planets have the same free-fall acceleration on the surface,but planet B has twice the radius of planet A.If planet A has mass m,what is the mass of planet B?

A) m/ $\sqrt { 2 }$
B) m
C) m $\sqrt { 2 }$
D) 4m
E) m/4