Two Planets Have the Same Surface Gravity, but Planet B $\sqrt { 2 }$

Two planets have the same surface gravity, 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