Which conditions are classified as restrictive lung diseases?

Restrictive lung diseases are characterized by a reduction in lung volume, leading to difficulty in fully expanding the lungs during inhalation. This group of diseases does not obstruct airflow but rather restricts the ability of the lungs to expand due to stiffness or damage to lung tissue, pleura, or the chest wall.

Pulmonary fibrosis, sarcoidosis, and pleural effusion directly impact lung compliance and the ability to inflate the lungs. Pulmonary fibrosis involves scarring of lung tissue, which decreases lung capacity and gas exchange efficiency. Sarcoidosis can cause granulomas that replace healthy lung tissue, increasing stiffness and reducing lung volumes. Pleural effusion refers to fluid accumulation in the pleural space, which can compress the lungs and limit their expansion.

In contrast, chronic bronchitis and emphysema primarily involve airflow obstruction, thus classifying them as obstructive lung diseases rather than restrictive. Asthma and COPD also primarily obstruct airflow, not restricting lung expansion in the same manner as restrictive diseases. Interstitial lung disease and pulmonary edema may suggest some overlap with restrictive patterns but do not encapsulate the same variety of restrictive conditions as the correct choice. Therefore, option B accurately identifies conditions that represent the restrictive lung disease classification.