$\text { Find the derivative of the function } f ( x ) = - 5 x ^ { 3 } - 2 \sin ( x ) \text {. }$

Multiple Choice

$\text { Find the derivative of the function } f ( x ) = - 5 x ^ { 3 } - 2 \sin ( x ) \text {. }$

A) $f ^ { t } ( x ) = - 15 x ^ { 2 } + 2 \cos ( x )$
B) $f ^ { t } ( x ) = - 10 x ^ { 2 } - 2 \cos ( x )$
C) $f ^ {t } ( x ) = - 5 x ^ { 2 } - 2 \cos ( x )$
D) $f ^ {t } ( x ) = - 5 x ^ { 2 } + 2 \cos ( x )$
E) $f ^ { t } ( x ) = - 15 x ^ { 2 } - 2 \cos ( x )$