Final answer:
Naïve B and T cells are immune cells that have not encountered their specific antigen. Naïve B cells are part of the humoral response, maturing into plasma cells producing antibodies. Naïve T cells contribute to the cell-mediated response against infected cells.
Step-by-step explanation:
Naïve B and T Cells
Naïve B and T cells are lymphocytes that have not yet encountered their specific antigens. In the immune system, naïve B cells become activated when they bind to an antigen; this leads to their maturation into plasma cells which produce antibodies as part of the humoral immune response. Conversely, naïve T cells, upon activation, are involved in the cell-mediated immune response, which targets infected cells.
The correct answer to the student's question is c) A cell that has not yet encountered its specific antigen. This is because the term 'naïve' refers to the state of these cells before they are activated by exposure to an antigen, which is necessary for them to develop into their respective effector forms.