<prompt> Common carotid bifurcates at which border of thyroid cailage?SuperiorInferiorLateralMedial  <response>: Common carotid aery bifurcates at superior border of lamina of thyroid cailage of larynx at C3 veebral level. At lower border of C6 , ending of larynx and pharynx and beginning of trachea and oesophagus. 