Let $y = \sin u + \cos u$ And $u = 4 x ^ { 2 } + 5$

Multiple Choice

Let $y = \sin u + \cos u$ and $u = 4 x ^ { 2 } + 5$ By the Chain Rule, $\frac { d y } { d x }$ is

A) $\cos ( 8 x ) - \sin ( 8 x )$
B) $\cos ( 8 x ) + \sin ( 8 x )$
C) $\cos \left( 4 x ^ { 2 } + 5 \right) - \sin \left( 4 x ^ { 2 } + 5 \right)$
D) $\cos \left( 4 x ^ { 2 } + 5 \right) + \sin \left( 4 x ^ { 2 } + 5 \right)$
E) $8 x \left[ \cos \left( 4 x ^ { 2 } + 5 \right) - \sin \left( 4 x ^ { 2 } + 5 \right) \right]$