What divides into two branches that lead to the lungs?

The trachea is the correct answer because it is the large airway that serves as the main passage for air to travel from the throat to the lungs. It branches into two primary bronchi—left and right—which then enter the corresponding lungs. This branching system allows air to be distributed throughout the lungs for gas exchange.

The bronchioles, while important in the respiratory system, are smaller airways that branch off from the primary bronchi and do not serve as the primary division point for airflow. Alveoli, on the other hand, are the tiny air sacs in the lungs where gas exchange occurs but are not involved in dividing air passages. The term "lungs" refers to the organs themselves and does not indicate any branching structure. Thus, the trachea is the correct structure that divides into two branches leading to the lungs.