Read the following passage and answer the questions that follow :-
In a study to test a new vaccine against the viral disease, mouse model testing is done. In this process, mice are vaccinated and their blood samples were tested. Mice developed mild disease symptoms. After a few days, those mice were again infected with the virus. This time they do not show any disease symptoms. Their blood samples were tested. Two graphs show antibody concentration for the first and second infection in mice blood.

How does vaccination work?

All of these.

All of the statements play a role in how vaccination works:

1. The immune system produces antibodies that stay in the blood: When a vaccine containing weakened or inactive parts of a pathogen (such as its proteins or genetic material) is introduced into the body, it triggers the immune system to respond. This response includes the production of antibodies by B cells, which circulate in the blood and target the specific pathogen.
2. Memory lymphocytes remain in the body to fight off any future infection with the same pathogen: Vaccines also stimulate the creation of memory cells—memory B cells and memory T cells. These cells "remember" the pathogen and stay in the body even after the initial immune response has subsided. If the body encounters the same pathogen again, these memory cells can quickly recognize and respond to it, preventing or reducing the severity of the infection.
3. Antigenic proteins of pathogens generate a primary immune response and the memory B and T cells: Vaccines contain antigenic components of pathogens that stimulate the immune system to generate a primary immune response. This primary response involves the activation of B and T cells specific to that pathogen. After the initial encounter, memory cells are produced, which provide long-term immunity upon re-exposure to the pathogen.

So, all these statements are part of the process of how vaccination works to prepare the immune system to recognize and defend against specific pathogens in the future.