In an Experiment in Which Long-Distance Runners Were Tested for Pain

In an experiment in which long-distance runners were tested for pain tolerance, ran a mile, and then were tested again for pain tolerance.The researchers found that

A) only half of the runners increased their pain tolerance by a minimal amount.
B) a little less than half of the runners could withstand pain about 70 percent longer than before.
C) all of the runners could withstand pain about 70 percent longer than before.
D) none of the runners increased their pain tolerance.