
Passage: People who take part in taekwondo are healthier than those who don't usually take part in taekwondo, so taekwondo helps to improve their health.
Question: Which of the following options, if correct, is the most likely to challenge the above conclusion?
A. A.Every year, a few people are injured by accidents in Taekwondo
B. B.Taekwondo can train people's reaction ability and enhance people's agility
C. C.Only healthy people take part in Taekwondo
D. D.Men prefer Taekwondo to women
Answer: