$\text { Find the derivative of the function } y = 8 \cos 4 x \text {. }$

Multiple Choice

$\text { Find the derivative of the function } y = 8 \cos 4 x \text {. }$

A) $y ^ { t} = - 4 \sin 4 x$
B) $y ^ { t } = - 8 \sin 4 x$
C) $y ^ { t } = - 32 \sin 4 x$
D) $y ^ { t } = 32 \cos 4 x$
E) $y ^ { t} = - 32 \cos 4 x$