C. Choose the true sentence. 1) She felt happy for her friends. 2) She felt angry and resentful. 3) She felt sad and envy. 4) She ignored them completely.

The correct answer is **3) She felt sad and envy.** **Explanation:** The passage indicates that Mary felt envious of her friends who were at the concert, as she was stuck in bed. The text also mentions that she felt like she was watching a movie where all the best parts happened without her and couldn't help but feel a little envy toward everyone else who was having the night of their lives without her.