Answer: C) The line "It is not night when I do see your face" creates a mood of romantic love.
Step-by-step explanation: In the given passage from Act II, Scene 1 of "A Midsummer Night's Dream" by William Shakespeare we can see Helens talking to Demetrius, and telling him that he is the world to her and that when she sees his face, for her it isn't night time anymore. So as we can see, the line "It is not night when I do see your face" creates a romantic mood between Helena and Demetrius, so the correct answer is option C.