Answer :
Surfactant deficiency due to undeveloped lungs (in premature infants) suggest respiratory distress in an infant, but would be less likely to be observed in an adult beacuse in adults , lungs are fully developed and lack of surfactant is less.
Explanation:
Respiratory distress syndrome is a type of neonatal disease of respiration ,caused by deficiency of the surfactant produced by type II alveolar cells in the lungs most commonly in premature infants.
Normally , the lungs of the fetus start the formation of the surfactant during the third trimester (26 weeks through labor and delivery ) but in the premature infants , the lungs are not totally developed , hence lack of surfactant production results in the respiratory distress syndrome charactarized by inflammation of the airways due to the lack of the surface tension lowring effect of the surfactant.