Which example uses an in-text citation correctly , according to mla standards

The correct answer is A. A sentence of death costs the state "almost three times as much as a sentence of life in prison" (DeLon 147)

In text citations should be as brief as possible, which purpose is to guide the readers to the entry of the work cited. Where generally it only includes the author;s last name and the page number(s) of the information used. In this case using only those to pieces of information "DeLon 147"

its a hard situation i cant really answer because the essay is for you to write.