The correct option is D qQ4πϵ0R2 towards the position of the removed charge
Answer is D.
Q provides the centripetal force required for q to move in a uniform circular motion. The magnitude of the force is given as F=qQ4πε0R2.
Therefore, If one charge is removed then net force on Q is qQ4πε0R2 towards the position of removed charge as it is positive.