A baby was born on his due date, but doctors determined that a valve in his heart was too short to adequately pump blood to his body. The baby passed away after eight months. Which best describes the cause of his death?

The heart valve problem was present when the baby was born, so it is a congenital condition. Being born on his due date means he was not premature, and the question describes neither an accident nor sudden infant death syndrome (SIDS).

AI-written and checked against the verified answer.