A spring is stretched downward by a certain length and, as a result, exerts a force in the upward direction. What happens to the force exerted by the
spring if the length by which it is stretched is reduced by half?
A. The force exerted by the spring reduced by one quarter.
B. The force exerted by the spring is doubled.
C. The force exerted by the spring is reduced by half.
D. The force exerted by the spring remains unchanged.