Lung surfactant plays a critical role in facilitating the diffusion of oxygen through alveolar membranes. The primary function of surfactant is to enhance oxygen exchange in the lungs. This process is essential for efficient respiratory function.

1. The answer is: b) facilitates O2 diffusion through alveolar membranes
Lung surfactant facilitates O2 diffusion through alveolar membranes.
Solution
The answer is: b) facilitates O2 diffusion through alveolar membranes
Lung surfactant facilitates O2 diffusion through alveolar membranes.