Which of the Following Is Newton's Law of Universal Gravitation $F ( t ) = m \mathbf { a } ^ { \prime } ( t )$

Multiple Choice

Which of the following is Newton's Law of Universal Gravitation?

A) $F ( t ) = m \mathbf { a } ^ { \prime } ( t )$
B) $F ( t ) = m \left\| \mathbf { a } ^ { \prime } ( t ) \right\|$
C) $\mathbf { F } ( t ) = - \frac { \operatorname { GmM } \mathbf { r } ( t ) } { \| \mathbf { r } ( t ) \| }$
D) $\mathbf { F } ( t ) = - \frac { \operatorname { GmM } \mathbf { r } ( t ) } { \| \mathbf { r } ( t ) \| ^ { 2 } }$
E) $\mathbf { F } ( t ) = - \frac { \operatorname { GmM } \mathbf { r } ( t ) } { \| \mathbf { r } ( t ) \| ^ { 3 } }$