The body of a 35-year-old male, who has been in good health, is found in his bathtub. no medications or medical supplies other than tylenol, nyquil and a basic first aid kit, are found in his apartment. no water is found in his lungs. the autopsy reveals a low level of sugar in the blood, a moderate amount of alcohol, and an incomplete circular fracture on the skull. there are no tumors or damage to internal organs. what is the most probably manner of death?

a) accidental
b) homicide
c) natural
d) suicide