For a particle executing simple harmonic motion (SHM), let's analyze the situation at the mean position (equilibrium point).
The correct answer is (B) Velocity is maximum and acceleration is zero.
In simple harmonic motion (SHM), at the mean position (x = 0), the velocity is at its maximum and the acceleration is zero. The equations for SHM are: \[ V = \omega A \sqrt{1 - (x/A)^2} \] \[ a = -\omega^2 x \] At the mean position, x = 0, so acceleration (a) is zero and velocity is at maximum.