--- he is, mistakes he will make.
--- That’s true. That’s why he got a low mark again.
A. The more careful, the less
B. The more careless, the more
C. The more careful, the more
D. The more careless, the fewer
网友回答
A. The more careful, the less
(答案→)B. The more careless, the more
C. The more careful, the more
D. The more careless, the fewer
解析：本题考查的是the +比较级+主谓，the +比较级+主谓.careful的比较级为more careful.
第一句放在he is的后面，需要的是careful，因此将BD排除，而后文根据意思，That’s true. That’s why he got a low mark again.可知答案为B