The answer to the question would be letter d. I hope this helps. :)
1 noun
2 adjective
3 pronoun
“As Atticus tells Jem and Scout, a mockingbird does no harm and makes music for people to enjoy. Tom Robinson is like a symbolic mockingbird because of his innocence; he has not harmed anyone and is an admirable character who offers help to others. Because Tom is not guilty, it makes it "sinful" to harm him.”