Navi Has Realized That Whenever Her Friend Eloise Is Around

Navi has realized that whenever her friend Eloise is around, she begins to feel angry. If Navi draws an inference based on the covariation principle, what will she conclude?

A) There is no real connection between Eloise's arrival and Navi's feelings.
B) Navi must be doing something both to prompt Eloise to arrive and to make herself angry.
C) There is probably a third variable explaining the fact that Navi feels angry at the same time that Eloise shows up.
D) Eloise causes Navi to become angry.