A tube is being stretched while maintaining its cylindrical shape. The height is increasing at the rate of 2 millimeters per second. At the instant that the radius of the tube is 6 millimeters, the volume is increasing at the rate of cubic millimeters per second. Which of the following statements about the surface area of the tube is true at this instant? (The Volume V of a cylinder with radius r and height h is V = π.r^2h. The surface area S of a cylinder, not including the top and bottom of the cylinder, is S = 2πrh.

a. The surface area is increasing by 28π square mm per second.

b. The surface area is decreasing by 28π square mm per second.

c. The surface area is increasing by 32π square mm per second.

d. The surface area is decreasing by 32π square mm per second.