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