Answer:
see below
Step-by-step explanation:
In chickenpox vaccine , weakened/killed pathogens are introduced into the body to generate immune response. The first response is slow and is called primary response while the subsequent exposure with the same pathogen generates a highly intensified immune response which is known as secondary response .
This type of immunity which generates antibody against the virus particles by introducing them into the body is called active immunity . It lasts forever in the body as the immune system has the memory of first exposure with the pathogen and after coming in contact with the same pathogen it recognises it and generates immune response.
So the correct option would be,
- Marina was exposed to a weak form of chicken pox antigen.

Related information:-
Passive immunity:-
It is the type of immunity when performed antibodies are introduced in the body . Like in case of smallpox. This doesn't last long in the body and requires repeated infusions in the body after coming in contact with the same pathogen again.
Also , it is helpful when quick reponse is required against the antigen and we don't have time to wait for generating immune response like in case of snake bites .