<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 2-month-old boy is brought to the pediatrician for a routine check-up. His mother says he is feeding well and has no concerns. He is at the 85th percentile for height and 82nd percentile for weight. Immunizations are up-to-date. Results of serum hepatitis B surface IgG antibody testing are positive. Which of the following best explains this patients hepatitis B virus status?? A: Window period, B: Chronic infection, C: Spontaneous recovery, D: Vaccination reaction, E: Passive immunity,  <response>: This is a question about interpreting hepatitis B serology in an infant. The key information is that the patient is 2 months old and has a positive hepatitis B surface antibody. A positive surface antibody indicates prior exposure and immunity to hepatitis B. In an infant, this is most likely from passive transfer of maternal antibodies. Maternal screening and vaccination prevents transmission to the infant.The choices describe different stages of hepatitis B infection or immunity. Window period refers to early acute infection when surface antibody is not yet detectable. Chronic infection would be surface antigen positive. Spontaneous recovery and vaccination reaction would not apply to a 2 month old. Passive immunity from maternal antibodies best explains this scenario.E: Passive immunity 