Final answer:
True statement: T cells only recognize antigens presented on the cell's surface within major histocompatibility complex molecules.
Step-by-step explanation:
The statement that is true about T cells and their recognition of antigens is: T cells only recognize antigens on the cell's surface. T cells utilize their antigen receptor, which is a complex of two protein chains on their surface, to recognize antigens. The recognition process is specific to antigens that are foreign to the body and does not include self-antigens. T cells cannot recognize antigens without them being presented on the surface of cells within major histocompatibility complex (MHC) molecules. There are distinct roles for different types of T cells, with helper T cells aiding in the activation of other immune cells, regulatory T cells maintaining immune tolerance, and cytotoxic T cells destroying infected or malignant cells.