Final answer:
An infant is considered premature if it weighs less than 5.5 pounds or is born before 37 weeks' gestation. Full-term pregnancy lasts 36-40 weeks with an average newborn weight of about 7.5 pounds. Premature infants experience less growth time, potentially resulting in various health risks.
Step-by-step explanation:
The classification of an infant as premature is based on birth weight and the duration of gestation. According to the definitions provided, an infant is considered premature if it "A) weighs less than 5.5 pounds or is born before 37 weeks' gestation." A full-term pregnancy is usually between 36-40 weeks, and the average weight of a newborn that has reached full term is approximately 7.5 pounds. Premature infants, those born before the completion of 37 weeks of gestation, have not had the same opportunity for growth and development in the uterus, which can lead to low birth weight and other health risks.
In summary, option A is the correct choice because it accurately reflects the definition of a premature infant based on both birth weight and gestational age, which are critical factors in the determination of prematurity.