Answer:
C. she, and I
Explanation:
What this sentence is missing are subject pronouns, that is to say, pronouns (words replacing nouns) that act as the subjects of the sentence, that is to say, that performs the main action which is "finished the test early".
There are seven subject pronouns: he, she, it, they, you, we and I. And since option C is the only choice that contains subject pronouns: she and I, it is the correct option.
The correct sentence is Ellen, Jan, she and I finished the test early.
