Final answer:
The answer to the student's question is D. T cell, which is not a professional antigen-presenting cell. Professional APCs include macrophages, dendritic cells, and B cells, with T cells being the recipients of information from APCs for the adaptive immune response.
Step-by-step explanation:
The student's question asks which of the following is not an example of a professional antigen-presenting cell (APC): A. B cell, B. Dendritic cell, C. Macrophage, D. T cell. The correct answer is D. T cell.
Professional antigen-presenting cells include macrophages, dendritic cells, and B cells. These cells have the ability to present antigens specifically for the purpose of activating T cells. Macrophages and dendritic cells are also phagocytes, which means they can engulf and digest pathogens. B cells, although they do not phagocytize, can present antigens to T cells to initiate the production of antibodies. However, T cells themselves do not act as APCs; instead, they are the recipients of the information presented by APCs and are critical to the adaptive immune response.