Driving at a constant speed, Sharon usually takes 180 minutes to drive from her house to her mother's house. One day Sharon begins the drive at her usual speed, but after driving 31 of the way, she hits a bad snowstorm and reduces her speed by 20 miles per hour. This time the trip takes her a total of 276 minutes. How many miles is it from Sharon's house to her mother's house?<spanclass=′latex−bold′>(A)</span>132<spanclass=′latex−bold′>(B)</span>135<spanclass=′latex−bold′>(C)</span>138<spanclass=′latex−bold′>(D)</span>141<spanclass=′latex−bold′>(E)</span>144