The distribution of weights of female college cross-country runners is approximately normal with mean 122 pounds and standard deviation 8 pounds. Which of the following is closest to the percent of the runners who weigh between 114 pounds and 138 pounds? 
选项为:A:18\%  B:32\%  C:68\%  D:82\%  E:95\%  请回答其中一个选项.