Alfred Alder, a famous psychiatrist, had an interesting experience. When he was a small boy he got off to a poor start in arithmetic. His teacher got the idea that he had no ability in arithmetic, and told his parents what she thought in order that they would not expect too much of him. In this way, they too developed the idea, "Isn't it too bad that Alfred can't do arithmetic?" He accepted their mistaken estimate of his ability, feeling that it was useless to try, and that he was very poor at arithmetic, just as they expected. One day he became very angry at the teacher and the other students because they laughed when he said he saw how to do a problem which none of the other students had been able to solve. Adler succeeded in solving the problem. This gave him confidence. He rejected the idea that he couldn't do arithmetic and was determined to show them that he could. His anger and his new found confidence stimulated him to go at arithmetic problems with a new spirit. He now worked with interest, determination, and purpose, and he soon became extraordinarily good at arithmetic. He not only proved that he could do arithmetic, but he learned early in life from his own experience that, if a person goes at a job with determination and purpose, he may astonish himself as well as others by his ability. This experience made him realize that many people have more ability than they think they have, and that lack of success is as often the result of lack of knowledge of how to apply one's ability, lack of confidence, and lack of determination as it is the result of lack of ability. In Alfred's opinion, if a person is unsuccessful, he may be  _  .
slow- thinking. disabled self-centered undetermined
Question: Alfred Alder, a famous psychiatrist, had an interesting experience. When he was a small boy he got off to a poor start in arithmetic. His teacher got the idea that he had no ability in arithmetic, and told his parents what she thought in order that they would not expect too much of him. In this way, they too developed the idea, "Isn't it too bad that Alfred can't do arithmetic?" He accepted their mistaken estimate of his ability, feeling that it was useless to try, and that he was very poor at arithmetic, just as they expected. One day he became very angry at the teacher and the other students because they laughed when he said he saw how to do a problem which none of the other students had been able to solve. Adler succeeded in solving the problem. This gave him confidence. He rejected the idea that he couldn't do arithmetic and was determined to show them that he could. His anger and his new found confidence stimulated him to go at arithmetic problems with a new spirit. He now worked with interest, determination, and purpose, and he soon became extraordinarily good at arithmetic. He not only proved that he could do arithmetic, but he learned early in life from his own experience that, if a person goes at a job with determination and purpose, he may astonish himself as well as others by his ability. This experience made him realize that many people have more ability than they think they have, and that lack of success is as often the result of lack of knowledge of how to apply one's ability, lack of confidence, and lack of determination as it is the result of lack of ability. In Alfred's opinion, if a person is unsuccessful, he may be  _  .
A. slow- thinking.
B. disabled
C. self-centered
D. undetermined
Answer: