Which Transformation Was Not Performed on Y=cos X $y=-4 \cos \left(2 x+\frac{\pi}{3}\right) ?$

Multiple Choice

Which transformation was not performed on y=cos x to obtain $y=-4 \cos \left(2 x+\frac{\pi}{3}\right) ?$

A) Vertical stretch by a factor of 4
B) Reflection through the x -axis
C) Horizontal stretch by a factor of 2
D) Horizontal shrink by a factor of $\frac{1}{2}$
E) Horizontal shift left $\frac{\pi}{6}$ units