2010 AMC 10A Problem 22

Eight points are chosen on a circle, and chords are drawn connecting every pair of points. No three chords intersect in a single point inside the circle. How many triangles with all three vertices in the interior of the circle are created?

\mathrm{(A)}\ 28 \qquad \mathrm{(B)}\ 56 \qquad \mathrm{(C)}\ 70 \qquad \mathrm{(D)}\ 84 \qquad \mathrm{(E)}\ 140

Full credit goes to MAA for authoring these problems. These problems were taken on the AOPS website.