Ten points are spaced equally around a circle. How many different chords can be formed by joining
any 2 of these points? (A chord is a straight line joining two points on the circumference of a circle.)<spanclass=′latex−bold′>(A)</span>9<spanclass=′latex−bold′>(B)</span>45<spanclass=′latex−bold′>(C)</span>17<spanclass=′latex−bold′>(D)</span>66<spanclass=′latex−bold′>(E)</span>55