Final answer:
Choanal atresia is the condition where bone or tissue blocks the nasal airway, causing breathing difficulties, and is present from birth. It is a specific case of airway obstruction, different from sleep apnea, which is characterized by pauses in breathing during sleep. The correct option is c.
Step-by-step explanation:
Choanal atresia is a condition where the nasal airway is obstructed by bone or tissue, causing difficulty breathing unless crying or breathing through their mouth. It is a congenital defect, which means it is present at birth. The blockage can occur in one or both nasal passages and is due to the abnormal bony or membranous partition between the nose and the pharynx. This results in the inability to pass air from the nose into the throat and lungs.
In comparison, sleep apnea is a disorder characterized by pauses in breathing during sleep, usually because of a physical blockage of airflow. Sleep apnea can cause poor sleep quality and is associated with symptoms such as fatigue, irritability, and a dry throat upon waking, often related to excessive snoring. While choanal atresia and sleep apnea both involve obstruction of air flow, choanal atresia is specifically related to a blockage in the nasal cavity that is present at birth.