Peter is a 40 year old male who came to the office with complaints of anxiety, sadness, nightmares, and difficulties concentrating. He also reported poor memory, low libido, feelings of guilt, despair, hopelessness and helplessness and occasional suicidal thoughts.

i believe the answer is d : )

what are the lines. come on!

are there multiple choice options?

many is the pronoun that is used in this sentence. many is a quantifier that determines the amount of discoveries. when we use quatifiers followed by nouns, they act as determiners, but when they are used without a noun, as it is this case, they are pronouns.