Which level does trachea divides into two right and left primary bronchi?

 

Concept: Larynx and lungs are connected by a long, U-shaped tube called the trachea. The windpipe is another name for the trachea. 

Your respiratory system relies on it heavily. 

Air enters your lungs through your larynx when you breathe in. 

The trachea splits into the right and left principal bronchus at the mediastinum at the level of the fifth thoracic vertebra.

Hence option 3 is correct answer