A student attaches a block to a vertical spring so that the block-spring system will oscillate in simple harmonic motion if the system is released from rest at a vertical position that is not the system's equilibrium position. Which of the following explanations is correct about why the system oscillates in simple harmonic motion about the block-spring system's equilibrium position?
a. The restoring force from the spring causes the block to accelerate towards the equilibrium position, creating oscillations.
b. The weight of the block creates a restoring force when the block is displaced from the equilibrium position, causing oscillations.
c. The friction between the block and the spring creates a periodic restoring force, leading to simple harmonic motion.
d. The air resistance acting on the block-spring system causes it to oscillate about the equilibrium position in simple harmonic motion.
