Answer:
That
Step-by-step explanation:
We can find our answer by process of elimination:
Let's fill in the blank to each question and see how each sounds and how it relates to the correct relative pronoun.
I’ve lost the notes that I took in that meeting.
"That" seems to sound alright.
I’ve lost the notes who I took in that meeting.
"Who" does not sound right.
I’ve lost the notes whichever I took in that meeting.
"Whichever" does not sound right.
I’ve lost the notes whom I took in that meeting.
"Whom" does not sound right.
Since all others do not sound right we can conclude that "That" is the correct answer.
Check:
A relative pronoun is a type of pronoun that often introduces dependent (or relative) clauses in sentences. They also can stand alone as the subject or object of a sentence. There is a specific list of relative pronouns, and here they are: who, whoever, whom, whomever, that, which, when, where, and whose.
In that case, we can see that the word that is a relative pronoun. Thus, our answer of "That" is correct. Also it refers to a thing not a person.