if x is positive, which of the following could be the correct ordering of 1/x, 2x, x^2?

I. x^2 < 2x < 1/x
II. x^2 < 1/x < 2x
III. 2x < x^2 < 1/x

A. None
B. I only
C. III only
D. I and II only
E. I, II and III