Emphysema impairs gas exchange via alveolar damage Steps:

• Identify emphysema as alveolar wall destruction in COPD, reducing lung surface area.
• Recall key effects: decreased diffusion capacity due to fewer alveoli and thickened barriers.
• Evaluate typical statements: 1 (reduced surface area), 2 (increased dead space), 3 (V/Q mismatch).
• Select options matching true effects: 1 and 3 align with core pathophysiology.

Why C is correct:

• C (1 and 3 only) matches emphysema's reduced alveolar surface area (1) and ventilation-perfusion imbalance (3), per Fick's law of diffusion.

Why the others are wrong:

• A includes 2 (increased dead space), which is more emphysema-related but not always primary for gaseous exchange.
• B omits 3, ignoring V/Q mismatch central to hypoxemia.
• D omits 1, neglecting core surface area loss.

Not enough information on exact statements 1-3 for full precision.

Final answer: C