Final answer:
The correct option is Thirst. Excessive urination, excessive thirst, and persistent hunger are the three cardinal signs of diabetes mellitus caused by problems with insulin and blood glucose regulation.
Step-by-step explanation:
Excessive urination, excessive thirst, and persistent hunger are the three cardinal signs of diabetes mellitus. These symptoms are caused by the body's inability to regulate blood glucose levels due to problems with the pancreatic hormone insulin.
Excessive urination occurs because the kidneys excrete more urine in an attempt to rid the blood of excess glucose, while excessive thirst is a result of the body's dehydration from using water to dilute the urine. Persistent hunger occurs because the body cells are unable to access glucose in the bloodstream.