Which of the following signs respiratory distress is typically unique to infants and children?

The correct answer is Nares flaring.

Nares flaring is a sign of respiratory distress that is typically unique to infants and children. It occurs when the nostrils widen and flare out during breathing, indicating increased effort to breathe. This is because infants and children have narrower airways and less developed respiratory muscles, making them more susceptible to respiratory distress.