Which of the following is a potential airway obstruction cause in infants?

The correct answer highlights that an infant's small tongue can contribute to potential airway obstruction. In infants, the proportion of the tongue to the oral cavity is larger compared to adults, which might seem counterintuitive. However, what is crucial here is that the size and positioning of the tongue can lead to it being displaced more easily during an obstruction event, particularly when the infant is in a supine position. This situation can severely compromise airway patency if the tongue falls back against the pharyngeal wall, especially if the infant is not alert or is in an altered state of consciousness.

Other factors, while they may play a role in airway management, do not directly result in airway obstruction. For example, the infant's large head is more significant in terms of how they position themselves rather than causing an obstruction on its own. Similarly, while the respiratory muscles may be less developed in infants, weak respiratory muscles primarily affect breathing efficacy rather than causing immediate airway blockage. Likewise, while the nasopharyngeal structure is different in infants, it is not the size of the structures themselves that lead to obstruction; rather, the mechanism by which the airway is maintained is more influenced by the size relationship among the oral cavity, tongue, and throat.