Which of the Following Situations Can Best Be Characterized as an Example

Multiple Choice

Which of the following situations can best be characterized as an example of passive immunity?

A) A 6-month-old infant receives his scheduled immunization against measles, mumps, and rubella.
B) A 9-year-old boy is immune to chicken pox after enduring the infection before 1 year.
C) An 8-year-old girl recovers from a respiratory infection after intravenous antibiotic treatment.
D) A 6-week-old infant receives antibodies from his mother's breast milk.