Let △A0B0C0 be a triangle whose angle measures are exactly 59.999∘, 60∘, and 60.001∘. For each positive integer n define An to be the foot of the altitude from An−1 to line Bn−1Cn−1. Likewise, define Bn to be the foot of the altitude from Bn−1 to line An−1Cn−1, and Cn to be the foot of the altitude from Cn−1 to line An−1Bn−1. What is the least positive integer n for which △AnBnCn is obtuse?
<spanclass=′latex−bold′>(A)</span>10<spanclass=′latex−bold′>(B)</span>11<spanclass=′latex−bold′>(C)</span>13<spanclass=′latex−bold′>(D)</span>14<spanclass=′latex−bold′>(E)</span>15