Which shows the expressions rewritten with the least common denominator?

7x-2/4x^2 and x-1/8x

A. 28x-8/16x^2 and 2x^2-2x/16x^2
B. 14x-4/8x^2 and 2x-2/8x^2
C. 28x^2-8x/16x^3 and 2x^3-2x^2/16x^3
D. 14x-4/8x^2 and x^2-x/8x^2