Final answer:
The correct answer is B) Cilia and mucus. Cilia are hair-like structures that, along with mucus, trap and remove foreign particles from the airways, aiding in the protection of the respiratory system.
Step-by-step explanation:
The cilia and the mucus both trap foreign objects in the airways, which is option B) Cilia and mucus. The bronchi and bronchioles of the lungs play a vital role in respiratory health. The lungs produce mucus, a sticky substance that traps particulates such as dust and germs. Cilia are small, hair-like projections found lining the walls of the bronchi and bronchioles. These cilia beat in unison to move mucus and trapped particles up to the throat, where they can be swallowed and eliminated via the esophagus.
The mucociliary escalator is how the respiratory system protects itself from harmful substances in the air. This system includes mucus-producing cells and cilia which continually move to sweep away the mucus and any debris toward the outside of the body.