A Spring in Equilibrium Is 0

Multiple Choice

A spring in equilibrium is 0.2 meters long and an external force of 0.5 Newtons stretches the spring to a length of 0.24 meters. The work done by the spring in stretching it from equilibrium to 0.28 meters, in Newton-meters, is
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A) -0.8
B) -0.5
C) -0.12
D) -0.04
E) -0.09