<prompt> Surest sign of brain stem deathAbsent Dolls eye reflexFixed dilated pupil not reacting to lightCheyne Stokes breathingDecerebrate posture  <response>: B i.e. Fixed dilated pupil not responding to light Cooling of body rigor mois is a sign of molecular or cellular death. - Somatic systemic, clinical or brain death is cessation of spontaneous breathing, circulation and brain activity as indicated by flat isoelectric EEG, deep unconsciousness with no response to external stimuli or internal need. Surest sign of brain stem death is fixed dilated pupil not constricting responding to light.Q 