A cylindrical tank with radius 4 feet and height 9 feet is lying on its side. The tank is filled with water to a depth of 2 feet. What is the volume of the water, in cubic feet?
Answer Choices
A. 24 \pi-36 \sqrt{2}
B. 48 \pi-36 \sqrt{3}
C. 24 \pi-24 \sqrt{3}
D. 36 \pi-36 \sqrt{3}
E. 36 \pi-24 \sqrt{2}