This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Anaesthesia
All of the following signs confirm the brain death except 
Select and explain. 
A. Hypothermia, B. Absent corneal reflex, C. Dilated & fixed pupils, D. No heart movements
A: Hypothermia
Answer: A: Hypothermia 
Explanation: (A) Hypothermia > Brain death is present when there is irreversible loss of all brain function, both brain-stem function and cortical (hemisphere) function.> Brain death criteria -- Loss of brainstem function & Absent cranial nerve reflexes - Pupillary light reflex; Corneal reflex; Oculo vestibular reflex (cold caloric test; No gag reflex)> Absent respiratory brain stem reflexes is done by Apnea test: Loss of cortical function (No spontaneous movement; no response to external stimuli); Irreversibility> Brain death is present when there is irreversible loss of brain function (criteria ? loss of brainstem function) absent cranial nerve reflexes, pupillary light reflex, corneal reflex, oculo vestibular reflex.