A 12-year-old boy with a history of ventricular septal defect presents with heart failure, a bulging praecordium, and murmurs. What complication best explains his condition?

Correct Answer: B

Rationale: Aortic valve regurgitation can develop due to progressive damage from turbulent blood flow, leading to volume overload and heart failure.

Correct Answer: C

Rationale: Approximately 90% of infants infected with hepatitis B at birth become chronic carriers due to an immature immune response, leading to prolonged viral persistence.

Correct Answer: A

Rationale: Hypoxic-ischemic encephalopathy is a common cause of seizures in newborns, especially those occurring shortly after birth. The other causes are possible but less common.

Correct Answer: B

Rationale: Vaccination does not amplify anaphylaxis, while infections, stress, and physical activity can increase susceptibility.

Correct Answer: C

Rationale: Hodgkin disease survivors have the highest cumulative incidence of second malignancies due to chemotherapy and radiation exposure.