PASCAL 2001 Problem 22

In the diagram, AB and BD are radii of a circle with center B. The area of sector ABD is 2\pi, which is oneeighth of the area of the circle. The area of the shaded region is

Image

Answer Choices
A. 2\pi-4
B. \pi
C. 2\pi-2
D. 2\pi-4.5
E. 2\pi-8