A 2-year-old patient has been diagnosed with vesicoureteral reflux. The most effective antibiotic for prophylaxis in this age group is:

Rationale:
A. Referral to a specialist is not immediately necessary when physical development is normal and there are no other concerning findings.
B. Measuring FSH and LH is indicated if there are signs of delayed puberty or abnormal secondary sexual characteristics, which are absent in this case.
C. hCG testing is used to assess for pregnancy, which is not relevant in a 14-year-old with normal pubertal development and no history suggesting pregnancy.
D. Reassurance and education are appropriate, as menarche typically occurs around Tanner stage 3–4, and variation in timing is normal. Most healthy adolescents who have normal physical development and no other symptoms will begin menstruating by age 15.

Rationale:
A. While perinatal mortality is higher in preterm infants compared with term infants, it is a consequence rather than a direct risk factor.
B. Asphyxia can occur in both term and preterm infants and is not specific to prematurity.
C. Cardiovascular complications may arise but are only one aspect of the broader risks associated with prematurity.
D. Prematurity-related complications encompass the full spectrum of health risks preterm infants face, including respiratory distress syndrome, intraventricular hemorrhage, thermoregulation difficulties, feeding intolerance, and infection susceptibility. These complications are directly related to the immaturity of organ systems in infants born before 37 weeks’ gestation, making them the most comprehensive risk category.