Final answer:
The statement that natural active immunity occurs when you get chickenpox from contact with an infected person is true. This process involves the body fighting off the virus and forming memory cells for long-term protection. It differs from artificial active immunity, which comes from vaccination.
Step-by-step explanation:
Natural active immunity occurs when an individual is exposed to a live pathogen, develops the disease, and then develops a lasting, protective immune response. Consequently, the statement that natural active immunity can occur when you get chickenpox from contact with an infected person is true. Once a person contracts chickenpox, the body's immune system fights off the virus, and memory cells specific to the varicella-zoster virus develop, contributing to long-term protection against future infections of chickenpox.
This is different from active immunity that results from immunization, where exposure to the pathogen is deliberate and controlled, typically using a weakened or inactive form. Immunization invokes a similar immune response and the formation of memory cells without causing the disease. The acquired immune response against chickenpox after natural infection is an example of natural active immunity, whereas the response from a vaccine would be considered artificial active immunity.