the only reason my sheets are wet every morning is because i sweat heavily for whatever reason. So my answer is F.
If you're sweating so heavily that the sheets are actually wet, you should see your doctor. "Night sweats" as they are called can be a symptom of several illnesses, some of which are serious, some of which are not.
8 Causes of Night Sweats by MedicineNet.com
Night sweats: What causes them? - MayoClinic.com
It could also just be that your bedroom is too warm, that you're using too many blankets, that you're having a reaction to alcohol, medication, or spicy foods, or that you just sweat a lot (hyperhydrosis).
As far as I can tell, I begin to sweat as soon as I fall asleep, even if the room is chilly, and regardless of what I'm wearing or whether or not I'm covered with a blanket. Sometimes I fall asleep watching TV and wake up just a few minutes later, sweating. But it my case it's a relatively light sweat, not bad enough to really wet the sheets.