The Work $\overrightarrow{\mathbf{F}}_{s p} \cdot d \overrightarrow{\mathbf{x}}$ Done by the Force Exerted by the Spring on a Force

Multiple Choice

The work $\overrightarrow{\mathbf{F}}_{s p} \cdot d \overrightarrow{\mathbf{x}}$ done by the force exerted by the spring on a mass attached to the end of the spring when the mass has displacement d $\overrightarrow{\mathbf{x}}$ is

A) always negative.
B) always positive.
C) negative half the time, positive the other half of the time.
D) positive more than it is negative.
E) negative more than it is positive.