In the diagram, ABC is a semi-circle with diameter AC, center O and radius 1. Also, OB is perpendicular to AC. Using AB as a diameter, a second semi-circle AEB is drawn. The region inside this second semi-circle that lies outside the original semi-circle is shaded, as shown. The area of this shaded region is
Answer Choices
A. \frac{\pi}{4}
B. \frac12
C. \frac{3\pi}{4}+\frac12
D. \frac34
E. \frac{\pi}{2}-\frac12
