2.

Answer and Explanation

Your Answer is

Correct Answer is H

Explanation

The subject predicate of the sentence is such books include... so contributed can only be the predicate of the clause. Since the clause lacks a subject and the modified object is a person, who is used.

which can only modify objects, not people.

Whom can only be an object in a clause, not a subject.

If item J deletes the leading word of the clause, the sentence has two predicates include/contributed, and there is no conjunction connection in the middle, which is wrong.