$\text { Find } \mathbf { r } ^ {t } ( t ) \cdot \mathbf { r } ^ {tt } ( t ) \text { given the following vector function: }$

Multiple Choice

$\text { Find } \mathbf { r } ^ {t } ( t ) \cdot \mathbf { r } ^ {tt } ( t ) \text { given the following vector function: }$
$\mathbf { r } ( t ) = - 3 t ^ { 3 } \mathbf { i } - 5 t ^ { 5 } \mathbf { j }$

A) $162 t ^ { 7 } \mathbf { i } + 2500 t ^ { 9 } \mathbf { j }$
B) 0
C) $162 t ^ { 3 } - 2500 t ^ { 7 }$
D) $162 t ^ { 3 } + 2500 t ^ { 7 }$
E) $162 t ^ { 8 } + 2500 t ^ { 8 }$