Tom is one of students in my class Yes . He usually prefers at home to playing

问题补充：

--- Tom is one of students in my class .

--- Yes . He usually prefers at home to playing outside .

A. the most hard-working , studying

B. more hard-working , to study

C. the most hard-working , to study

D. more hard-working , studying

答案：

(答案→)A. the most hard-working , studying

B. more hard-working , to study

C. the most hard-working , to study

D. more hard-working , studying

解析：根据in my class可知，本句应该是最高级，根据one of +形容词的最高级+名词复数的用法，应该排除BD；根据prefer doing to doing“喜欢干某事，而不喜欢某事”，是固定用法。所以本题选A。