What is the amplitude, period, and phase shift of f(x) = −3 cos(4x + π) + 6?

A. Amplitude = 3; period = pi over two; phase shift: x = negative pi over four
B. Amplitude = −3; period = pi over two; phase shift: x = pi over four
C. Amplitude = −3; period = negative pi over two; phase shift: x = negative pi over four
D. Amplitude = 3; period = 2π; phase shift: x = negative pi over four