Final answer:
Collapsed alveoli in newborns are caused by respiratory distress syndrome, which is a result of the lack of surfactant in their lungs.
Step-by-step explanation:
The collapse of alveoli in newborns is primarily caused by the lack of surfactant, a substance that reduces surface tension in the lungs. This condition is known as respiratory distress syndrome (RDS) and is a leading cause of death in premature infants. The lack of surfactant makes it difficult for the alveoli to inflate properly, resulting in respiratory difficulties.
Hyaline membrane disease is another term used to describe RDS. Treatments for RDS include administering surfactant to the infant's airways, which helps to alleviate the collapsed alveoli and improve lung function.
Therefore, the correct option for the question is B. Collapsed alveoli in newborns are caused by respiratory distress syndrome.