Their love is based on both physical and emotional attraction.
The use of imagery shows their love is predominantly physical. You can rule out D because although that may be true, it does not state anything relating to that in the small excerpt provided.
Agnostic means to believe in a higher power, but not one that necessarily coincides with a specific religion. It is not atheism and it is not theism. It is believing that there is something there (that could be a god(s)), so to speak.