What is the most likely exclamation for this repeated references?

Read the excerpt from a research essay published in a printed book. binge-watching television shows several times a week has a negative impact on people’s social lives. according to a study conducted by dr. cynthia toles, adults who binge-watched more than one show a week were more prone to insomnia and a less-healthy diet. further, "the process of watching several episodes of one show consecutively can cause changes to one’s sleep patterns” (toles). to follow mla citation rules properly, what does the author of this essay need to do? a.) add a citation after each sentence in the essay b.) include a page number after the author’s name c.) remove the reference to the name of the doctor d.) place an end quotation mark after the end parenthesis