The radius of a cylinder is increasing at a rate of 1 meter per hour, and the height of the clinder is decreasing at a rate of 4 meters per hour. At a certain instant, the base radius is 5 meters and the height is 8 meters. What is the rate of change of the volume of the cylinder at the instant? Recall that the volume of a cylinder is given by: V=rh B)-120 C) 60 m hr D)-80 A)-60 hr