Which of the following age ranges is classified as infant? 1) Born at gestational age <38 weeks 2) 0-4 weeks postnatal age 3) 1 month to 2 years of age (1 month to <12 months old) 4) 2-12 years of age (1-12 years old) 5) 12-21 years of age (13-16, 18 or 19 years old)
