Write a multi-choice question for the following article, with the given choices and answer: Article: Once when I was facing a decision that involved high risk, I went to a friend. He looked at me for a moment, and then wrote a sentence containing the best advice I've ever had: Be bold and brave -- and mighty forces will come to your aid. Those words made me see clearly that when I had fallen short in the past, it was seldom because I had tried and failed. It was usually because I had let fear of failure stop me from trying at all. On the other hand, whenever I had plunged into deep water, forced by courage or circumstance, I had always been able to swim until I got my feet on the ground again. Boldness means a decision to _ . And there is nothing mysterious about the mighty forces. They are potential powers we possess: energy, skill, sound judgment, creative ideas -- even physical strength greater than most of us realize. Admittedly, those mighty forces are spiritual ones. But they are more important than physical ones. A college classmate of mine, Tim, was an excellent football player, even though he weighed much less than the average player. "In one game I suddenly found myself confronting a huge player, who had nothing but me between him and our goal line," said Tim. "I was so frightened that I closed my eyes and desperately threw myself at that guy like a bullet -- and stopped him cold." Boldness -- a willingness to extend yourself to the extreme--is not one that can be acquired overnight. But it can be taught to children and developed in adults. Confidence builds up. Surely, there will be setbacks and disappointments in life; boldness in itself is no guarantee of success. But the person who tries to do something and fails is a lot better off than the person who tries to do nothing and succeeds. So, always try to live a little bit beyond your abilities--and you'll find your abilities are greater than you ever dreamed. Options: A His physical strength. B His basic skill. C His real fear. D His spiritual force. Answer: D His spiritual force. Question:
A:
What was especially important for Tim's successful defense in the football game?