In which of the following does the trachea divide at the point of the carina into the right and left primary bronchi?

Correct option is D

Ans. (d) Sol. The trachea bifurcates at the carina into the right and left primary bronchi at the level of the 5th thoracic vertebra (T5). This anatomical landmark is important for endotracheal intubation, bronchoscopy, and understanding airway physiology.
Explanation of Other Options:
· (a) 2nd thoracic vertebra (T2): Too high; the trachea is still in the upper thorax.
· (b) 3rd thoracic vertebra (T3): The trachea has not yet reached its bifurcation.
· (c) 4th thoracic vertebra (T4): Close, but the bifurcation occurs slightly lower at T5, particularly at the sternal angle (Angle of Louis).