The walls of the alveoli are composed of two types of cells, type I and type II alveolar cells. The function of type II alveolar cells is to . The walls of the alveoli are composed of two types of cells, type I and type II alveolar cells. The function of type II alveolar cells is to . replace mucus in the alveoli protect the lungs from bacterial invasion trap dust and other debris secrete surfactant

The walls of the alveoli are composed of two types of cells, type I and type II alveolar cells. The function of type II alveolar cells is to secrete surfactant.

Explanation:

Type II cells have great importance in the synthesis, storage, and secretion of lung surfactant, which acts to reduce surface tension and prevent collapse of the alveoli, reducing the pulmonary tension, it helps the respiratory mechanics, minimizing the energy that the lung tissue must provide to keep the gas exchange surface open and exposed during successive inspiration-expiration cycles. Type II cells comprise up to 14% of all alveolar epithelial cells.

c is the correct answer hope this !

layer 3 is younger than layer 6.