Answer:
b. F1=F2=F3=0 because there is no change in the horizontal motion of the arrows.
Explanation:
The three arrows in the given problem have been shot and it is assumed that air resistance can be neglected. The motions of the arrows are in horizontal direction and as such there is no obvious change in the horizontal motion of the three arrows. Therefore, the three forces are equivalent to one another and each force is equal to zero (i.e. F1=F2=F3=0).