In the function y-1 = (4x)² + 7, what effect does the number 4 have on
the graph, as compared to the graph of y = x^2?
A. It stretches the graph vertically by a factor of 4.
B. It shrinks the graph vertically to 1/4 the original height.
C. It stretches the graph horizontally by a factor of 4.
D. It shrinks the graph horizontally to 1/4 the original width.