Take a look at the sentence again:
Everyone points to Jeannine as an example of an excellent student because
she has an attentive attitude, detailed class notes, and __________.
The blank requires a noun phrase. You chose the fact that she gets As on everything, which is a noun phrase followed by an adjective clause. You thus have a parallelism error. Before you continue, review the rules for parallel structure.
Go back to the sentence to try again.