In the function. Y+3=(2x)^2+1 what effect does the number 2 have on the graph as compared to the graph y=x^2

A.it stretches the graph vertically by a factor of 2

B. It stretches the graph horizontally by a factor of 2

C. It shrinks the graph vertically to 1/2 the original height


D. It shrinks the graph horizontally to 1/2 the original width