Which of the following is a sign of respiratory distress in infants?

Nasal flaring is a significant indicator of respiratory distress in infants. When an infant is experiencing difficulty breathing, they may exhibit nasal flaring as a compensatory mechanism. This occurs when the nostrils widen during inhalation to allow more air to enter the lungs, suggesting that the child is struggling to breathe effectively. It is often accompanied by other signs of respiratory distress, such as retractions or grunting, and indicates that the infant's body is in a state of distress and may need immediate medical evaluation.

In contrast, sneezing is a reflex that can occur for various benign reasons, such as clearing irritants from the nasal passages. Yawning is not associated with respiratory distress; it is usually a sign of tiredness or a response to changes in oxygen or carbon dioxide levels. Frequent burping generally relates to feeding practices and does not indicate any respiratory issues or distress. These factors highlight why nasal flaring is a more clinically relevant sign in the context of respiratory distress.