Final answer:
Diffuse infiltrative disease of the lung parenchyma is indicative of Interstitial lung disease, which involves inflammation and scarring of the lung interstitium.
Step-by-step explanation:
Diffuse infiltrative disease of the lung parenchyma is indicative of Interstitial lung disease (C). This condition is characterized by the inflammation and scarring of lung tissue, specifically affecting the interstitium, which supports the alveoli (air sacs) in the lungs. It contrasts with obstructive diseases like chronic obstructive pulmonary disease (COPD) and asthma, where airflow is hindered due to airway obstruction, and with infectious conditions like pneumonia, where alveoli become inflamed and fill with fluid due to infection.