阅读下面短文，从每题所给的A、B、C、D四个选项中选出可以填入空白处的最佳选项。
On Oct. 11, hundreds of runners competed in a cross-country race in Minnesota. Melanie Bailey should have _ 41 _ the course earlier than she did. Her _42 _ came because she was carrying a _43 _ across the finish line.
As reported by a local newspaper, Bailey was more than two-thirds of the way through her _44 _ when a runner in front of her began crying in pain. She _45 _ to help her fellow runner, Danielle Lenoue. Bailey took her arm to see if she could walk forward with _46 _. She couldn’t. Bailey then _47 _ to let Lenoue climb onto her back and carried her all the way to the finish line, then another 300 feet to where Lenoue could get _48 _ attention.
Once there, Lenoue was _49 _ and later taken to a hospital, where she learned that she had serious injuries in one of her knees. She would have struggled with extreme _50 _ to make it to that aid checkpoint without Bailey’s help.
As for Bailey, she is more _51 _ about why her act is considered a big _52 _. “She was just crying. I couldn’t _53 _ her,” Bailey told the reporter. “I feel like I was just doing the right thing.”
Although the two young women were strangers before the _54 _, they’ve since become friends. Neither won the race, but the _55 _ of human kindness won the day.