Which transformations are needed to change the parent cosine function to the cosine function shown in the graph?
A
vertical compression of 2 , horizontal stretch to a period of pi over 4 , phase shift of pi over 4 units to the left, vertical shift of 2 units downB
vertical stretch of 2 , horizontal stretch to a period of 2 pi , phase shift of pi over 2 units to the right, vertical shift of 1 unit upC
vertical compression of 2 , horizontal compression to a period of 4 pi , phase shift of pi over 3 units to the left, vertical shift of 1 unit downD
vertical stretch of 2 , horizontal compression to a period of pi over 2 , phase shift of pi units to the right, vertical shift of 1 unit down