<prompt> During surgery for aortic arch aneurysm under deep hypothermic circulatory arrest which of the following anaesthetic agent administered prior to circulatory arrest that also provides cerebral protection?EtomidateThiopental SodiumPropofalKetamine  <response>: B Thiopental Sodium Uses of Thiopentone Sodium: Induction of anaesthesia; Maintenance of anaesthesia for short procedures; Basal narcosis by rectal administration; Treatment of status epilepticus; Reduction of intracranial pressure; Fordiagnostic operative neurological procedures. 