The First of Two Identical Boxes of Mass M Is $\degree$

Multiple Choice

The first of two identical boxes of mass m is sitting on level ground. The second box is sitting on a ramp that makes a 20 $\degree$ angle with the ground. The normal force of the level ground on the first box is NL; the normal force of the ramp on the second box is NR. Which statement is correct?

A) NR = NL = mg.
B) NL = mg; NR = mg sin 20 $\degree$ .
C) NL = mg; NR = mg cos 20 $\degree$ .
D) NL = mg; NR = -mg cos 20 $\degree$ .
E) NR = -NL = -mg.