The correct answer is: B. Zero.
The instantaneous center of rotation (ICR) is a point on a rigid body that appears to be stationary when the body is in motion. The ICR is always located on the line of action of the net external force acting on the body. When the angular velocity is zero, the ICR is at infinity. This is because the line of action of the net external force is then parallel to the direction of motion of the body, and the ICR must be located at a point on the line of action of the force.
Option A is incorrect because the ICR can be at any point on the body, not just at the center of mass. Option C is incorrect because the ICR can be at any point on the body, not just at a point where the angular velocity is maximum. Option D is incorrect because the ICR can be at any point on the body, not just at a point where the angular velocity is minimum.