There are various forms of pneumonia that tend to cause an excessive build-up of mucus in the lungs. What is the effect of this occurrence on the diffusion of gases?

The correct option is D Oxygen doesn’t easily diffuse into the blood and carbon dioxide can’t diffuse out easily
Pneumonia is a respiratory disorder. It leads to acute infection, and inflammation of the alveoli. As the alveoli get filled with mucus and pus, the exchange of gases becomes difficult. Hence, the oxygen in the blood is reduced. The causative agents of pneumonia are bacteria, protozoa, virus, fungi, and mycoplasma. Since the alveoli are hindered with mucus and pus, the diffusion of gases is also hindered across the membranes in the alveoli. Hence, oxygen doesn’t easily diffuse into the blood and carbon dioxide can’t easily diffuse out.