Please Read the Clinical Scenario, and Then Answer the Question

Please read the clinical scenario, and then answer the question that follow to become familiar with the traditional NCLEX question format.
Joseph is a 6-year-old male presenting to your pediatric office with chickenpox. He has had his infection for about 1 week, and his mom is concerned about Joseph’s 8-year-old sister, Judith, because she had a long, painful infection of chickenpox 2 years before. Of note, Joseph was not vaccinated against chickenpox when he was younger, because his mom did not think it was that serious of a virus, and she wanted to spare him the extra injection.
-When Joseph's mom expresses concern over Judith becoming reinfected,what is an appropriate response?

A) "Your concerns are valid,but Judith developed an active natural immunity to chickenpox because she's already been infected,so you don't need to worry."
B) "Your concerns are valid,and there is a high likelihood that Judith will become infected again.We should probably administer the vaccine."
C) "There's no way to protect Judith from becoming reinfected except to keep her at least 15 feet from Joseph at all times."
D) "There's no way of knowing how chickenpox infection works,or how transmission functions.I wish there was something more we could tell you."