A Mass of 0

Multiple Choice

A mass of 0.4 kg,attached to a spring with a spring constant of 80 N/m,is set into simple harmonic motion.What is the magnitude of the acceleration of the mass when at its maximum displacement of 0.2 m from the equilibrium position?
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A) zero
B) 20 m/s²
C) 10 m/s²
D) 40 m/s²
E) ​80 m/s²