In the function y + 3 = (2x)^2 +1, what effect does the number 2 have on the graph, as compared to the graph of y=x^2
A. It shrinks the graph vertically to 1/2 the original height.
B. It stretches the graph vertically by a factor of 2.
C. It stretches the graph horizontally by a factor of 2.
D. It shrinks the graph horizontally to 1/2 the original width.