Please answer the following question: Read the article and select the best answer. Article: A young girl decided to study judo despite the fact that she had lost her left arm in a car accident. The girl began lessons with an old Japanese judo instructor. The girl was doing well. So she couldn't understand why, after three months of training, the instructor had taught her only one move. "Instructor," the girl finally said, "Shouldn't I be learning more moves?" "This is the only move you know, but this is the only move you'll ever need to know," the instructor replied. Not quite understanding, but believing in her teacher, the girl kept training. Several months later, the instructor took the girl to her first tournament . Surprising herself, the girl easily won her first two matches. The third match proved to be more difficult, but after some time, her opponent became impatient. The girl used her one move to win the match. Still amazed by her success, the girl was now in the finals. This time, her opponent was bigger, stronger and more experienced. For a while, the girl appeared to be overmatched. Concerned that the girl might get hurt, the referee called a time-out . She was about to stop the match when the instructor intervened . "No," the instructor insisted, "Let her continue." Soon after the match restarted, her opponent made an important mistake: she dropped her guard. Instantly, the girl used her move to defeat her opponent. The girl had won the match and the tournament. She was the champion. On the way home, the girl and her teacher reviewed every move in each match. Then the girl asked what was really on her mind. "Instructor, how did I win the tournament with only one move?" "You won for two reasons," the teacher answered. "First, you've almost mastered one of the most difficult throws in all of judo. Second, the only known defense for that move is for your opponent to grab your left arm." Question: Why did the instructor teach the girl only one move? Options: A: Because three months' training isn't long enough for her to learn a new move B: Because the instructor thought the girl didn't have the ability to learn more C: Because the instructor know exactly the girl's strengths and weaknesses D: Because the girl is not confident enough to learn a new move
A:
C