单项选择题

Questions 18 to 20 are based on the following passage. At the end of the passage, you will be given 15 seconds to answer the questions.
Now listen to the passage.
What is the effective way to prevent the burnout of young athletes

A. To reduce their mental stress.
B. To increase their sense of success.
C. To make sports less competitive.
D. To make sports more challenging.