In an obese patient the most likely respiratory change is: (A) FRC is unchanged, (B) Alveolar hypo ventilation, (C) Residual volume is decreased, (D) Normal work of breathing
Answer is B. Obesity hypoventilation syndrome is characterized by :

Obesity.
Hypoxemia.
Hyper carbia.
Respiratory acidosis.
Pulmonary hypertension.
Right ventricular failure.