During his episode of DKA, Harrison answered "I'm so thirsty" to all questions. Which of the following best explains his polydipsia?
a. Hypoinsulinaemia increases the stimulation of the thirst centres in the hypothalamus
b. The glucose during hyperglycaemia stimulates the thirst center within the hypothalamus
c. The elevated alcohol levels in his blood stimulate the thirst centres in the hypothalamus
d. Hyperglycaemia causes osmotic diuresis and subsequent dehydration, which then stimulates the thirst centres