<prompt> Which aery is formed by joining of 2 veebral aeries?Basal aeryMiddle cerebralaeryPosterior cerebral aeryBasilar aery  <response>: Basilar aery is formed by the union of two veebral aeries at the lower border of pons. Middle cerebral aery is a branch of internal carotid aery. Posterior cerebral aery is a branch of basilar aery. Ref: Vishram Singh textbook of clinical neuroanatomy, second edition pg-174,176 