<prompt> Which of the following aery is likely to be involved in 3rd cranial nerve lesion?Anterior communicatingPosterior communicatingPosterior cerebralAnterior cerebral  <response>: Answer is B Posterior Communicating Aery: The occulomotor nerve CNIII courses in close relationship to the posterior communicating aery and is frequently compressed by an enlarging aneurysm of the posterior communicating aery. 