question: Which one of the following children with diarrhea requires antibiotics?
opa: A 3-month-old infant with rectal swab showing Salmonella growth
opb: A 10-year-old patient with stool culture positive for Salmonella whose bowel movements have decreased in frequency and volume
opc: A 4-year-old patient with sickle cell trait with stool culture showing Salmonella growth
opd: A 5-year-old patient with moderate bloody diarrhea that began after completing a course of amoxicillin for otitis media