Answer:
a) basilar
Explanation:
The basilar artery is an artery whose function is to supply of blood to the brain and central nervous system, thereby transporting oxygenated blood to the brainstem, cerebellum, and occipital lobes for maintaining normal brain function. This artery is 3 to 4 mm in diameter. The basilar artery is formed from the confluence of two vertebral arteries inside the cranium at the level of the medulla. The posterior cerebral arteries are formed by the bifurcation of the basilar artery, and they supply oxygenated blood to the occipital lobes and posteromedial temporal lobes.