Answer: 3 )it’s no use repining over unfinished test questions.
This excerpt uses the word "repine" in the sense of feeling sorry for a particular situation. It expresses a feeling of longing and discontent.
Option 1 and 4 refer to looking back at moments of the past that we have enjoyed and wish we could have them again. Although they are close in meaning, they do not express the feeling of discomfort that the excerpt has.
Option 2 does not mention any longing or discomfort, and it is also very vague.
Option 3 conveys a feeling of longing for a different situation and also of having a feeling of discomfort over being unable to change your situation. Therefore, it is the closest one in meaning to the excerpt.