article: The marathon  in my town usually takes place in hot weather. My job was to follow the runners to help those who needed medical help. "We should stay behind the last runner, so take it slowly," I said to the driver, Doug.
  As it began, the front runners started to disappear . Then I noticed a woman in blue running shorts and a white T-shirt. " Doug, look!" We knew we were watching our "last runner". Her feet turned in , yet her left knee turned out. Her legs were so crippled  that it seemed impossible for her to be able to walk. How could she run a marathon?
  We watched in silence as she slowly moved forward. We would move forward a little bit, then stop and wait for her. Then we would slowly move forward a little bit more. As I watched her try to put one foot in front of the other, I found myself breathing for her. I wanted her to stop, and at the same time, I hoped that she wouldn't. Finally, she was the only runner left in sight. When the finishing line came into sight, we found the cheering people had all gone home. She slowly crossed through the line and lifted her hands, full of happiness.
  I do not know the woman's name, but since that day she has become a part of my life. For her, it was about finishing what she had set out to do, no matter what. When I think things are too difficult and want to say "I just can't do it", I think of the last runner. Then I realize how easy the task before me really is.
question: The last runner had problems with her  _  .
options: head back legs arms