The teacher selected the student she could trust. who whom

Whom

Explanation:

While "whom" is a pronoun that refers to the subject of a sentence, "whom" refers to the object of a verb or a preposition, meaning that "whom" does not perform the main action, but, instead, it receives the action, or it can be found near a preposition such as "to" and "from".

In the sentence, the missing pronoun should refer to the student, and since the student is the object of the verb "selected" (because it is the one that is receiving the action and not performing it), the correct pronoun is "whom."

check your question

- "a.) it includes letters and books gathered over 1200 years, and consists of two parts.

- most of the new testament is letters from paul to the different churches, and since there's a new testament that means there is an old testament. "