Select the correct answer.
Roger pushes a box on a 30° incline. If he applies a force of 60 newtons parallel to the incline and displaces the box 10 meters along the incline, how much work will he do on the box?

A.
5.2 × 102 joules
B.
6.0 × 102 joules
C.
-5.2 × 102 joules
D.
-6.0 × 102 joules