Which sum could be used to find the difference in thickness (in inches) between sheeting A and Sheeting B. A= 1 7/20 B= 2 3/20

A: (-2 3/20)+(-1 7/20)

B: 2 3/20+ 1 7/20

C: 2 3/20 + (-1 7/20)

D:(-2 3/20) + 1 7/20