[Solved] Which statement about regulatory T cells (Tregs) is true? A) Tregs are similar to T-helper cells and cytotoxic T cells in that they are produced in the thyroid gland. B) Tregs differ from T-helper cells and cytotoxic T cells in that they are activated when they bind antibodies. C) Tregs suppress the cellular immune response against self antigens. D) Destruction of Tregs would severely reduce the recognition of non-self antigens. E) Activated Tregs secrete perforin, which stimulates proliferation of B cells. Microscopic Examination: The analysis of small objects or structures that cannot be seen with the naked eye, using a microscope. Epithelial Cells: Cells that line the surfaces of the body, such as skin, blood vessels, urinary tract, and organs, providing protection, absorption, and secretion functions. Bacteria: Microscopic, single-celled organisms found in virtually every environment on Earth, some of which are beneficial while others can cause diseases. Alkaline: Relating to or denoting substances that have a pH greater than 7, characterized by the presence of hydroxide ions (OH-).