Final answer:
Adoptive transfer of acquired immune responsiveness often entails transferring lymphocytes like B and T cells, which are crucial to adaptive immunity. The correct answer here is D. Lymphocytes.
Step-by-step explanation:
The adoptive transfer of acquired immune responsiveness typically involves the transfer of lymphocytes. These can include both B cells and T cells, which are critical to the adaptive immunity. In the context of this question, the correct option is D. Lymphocytes. This is because B cells, a type of lymphocyte, can generate antibodies upon encountering an antigen, and can give rise to plasma cells which produce antibodies. T cells, also lymphocytes, are essential for cell-mediated immunity and can be cytotoxic T lymphocytes, which directly attack and kill infected cells.
Passive immunity can occur when antibodies produced by one organism are transferred to another, providing immediate but temporary protection. Examples of this include the transfer of maternal antibodies to a fetus through the placenta or to a newborn through breast milk.