Suppose f(x) = x2 and g(x) = 4x. Which statement best compares the graph of g(x) with the graph of f(x)?
A. The graph of g(x) is the graph of f(x) shifted 4 units left.
B. The graph of g(x) is the graph of f(x) horizontally stretched by a
factor of 4.
C. The graph of g(x) is the graph of f(x) vertically compressed by a
factor of 4.
D. The graph of g(x) is the graph of f(x) vertically stretched by a
factor of 4.