Which is true about the two different trails used in the Iditarod race. A. The contestants on one trail race against contestants on the other B. One trail leaves Anchorage and the other trail goes back to Anchorage. C. Contestants travel on the northern trail to the halfway checkpoint and then travel to the finish line on the southern trail. D. Having two trails used on alternate years means that small villages along the trails host large groups of people passing through every other years rather than every year