Answer:
The correct answer is a. elevated ADH levels
Step-by-step explanation:
The function of ADH is to regulate the excretion of water from kidneys. As Dan has been lost in the desert for 2 days his body must be dehydrated and in stress which gives signal to hypothalamus gland to increase ADH level.
Once ADH level is increased his kidney starts reabsorbing as much water as it can preventing his body to become dehydrated and reduce his urine amount.
So the correct answer is a. elevated ADH levels