The Masses of Two Objects Are $M _ { 1 }$

The masses of two objects are $M _ { 1 }$ and $M _ { 2 }$ . The force of gravitation F between the masses is given by $F = \frac { G M M _ { 2 } } { d ^ { 2 } }$ where $G$ is a constant and $d$ is the distance between them. Solve for $M _ { 2 }$ .

A) $M _ { 2 } = \frac { F } { G M _ { 1 } d ^ { 2 } }$
B) $M _ { 1 } = \frac { F d ^ { 2 } } { G M _ { 2 } }$
C) $M _ { 1 } = \frac { F } { G M _ { 2 } d ^ { 2 } }$
D) $M _ { 2 } = \frac { F G M _ { 1 } } { d ^ { 2 } }$
E) $M _ { 2 } = \frac { F d ^ { 2 } } { G M _ { 1 } }$