The answer is B. An antitussive will help a cough by deterring the cough reflex.
I guess once you input the numbers into the correct places into the equation it would look like this :
PE = 50 * 9.8 * 5.0
PE = 2,450
If the force equals, for instance, 100 Newtons then 0.866 × 100 = 86.6 Newtons. This is the magnitude of the resultant force vector on the object.