Montag and Mildred think someone is at the door. Why doesn't the door-voice tell them if someone is there? Montag had turned it off before they started reading.
It seems that you have missed the necessary options for us to answer this question so I had to look for it. Anyway, here is the answer. The statement that best expresses the carpe diem theme in literature is this: <span>Make the most of life while you can. Carpe diem means "seize the day". Hope this helps.</span>