Question

lo 4.2. what is the function of smooth muscle in bronchioles?
regulate airflow by contracting and relaxing
aid in digestion by breaking down food particles
secrete mucus to trap pathogens
produce antibodies to fight infections
produce hormones to regulate metabolism

Explanation:

Smooth muscle in bronchioles contracts and relaxes. This action changes the diameter of bronchioles. When diameter changes, airflow is regulated. Other options are incorrect. Digestion is related to digestive system. Mucus secretion (by goblet cells) traps pathogens. Antibodies are produced by immune cells (like B - cells). Hormones for metabolism regulation are from endocrine glands.

Answer:

Regulate airflow by contracting and relaxing