Annoyed is not the answer because annoyed means irritated. Regretful is also definitely not the answer because regretful basically means being disappointed about something (mainly in the past). The words longing and admiring are left. Longing means to desperately want something, which does have a happier connotation than the other choices, but it still doesn't make sense. Finally, the word admiring means approval, which makes the most sense out of all the answers.
