The correct option is B Velocity of the particle is constant.
If a particle executes SHM about mean position x=0, we can say that
For a particle executing SHM, mean position is the point of equilibrium. Hence, the net force acting on it is equal to zero.
From (1), we can say that
Doing integration on both sides, we get
∴ we can say that, the velocity of particle executing SHM is not constant and is a function of the position of the particle.
Thus, option (b) is incorrect.