Final answer:
Super antigens are potent stimulators of T cells that can elicit a severe immune response through the widespread activation of T cells, leading to diseases like toxic shock syndrome due to the resulting cytokine storm.
Step-by-step explanation:
The correct answer to the question is B. Super antigens. These substances, which include some bacterial toxins, are known for their ability to stimulate T cells in a potent and broad manner, leading to diseases such as toxic shock syndrome. Unlike typical antigens, which activate specific T cells, superantigens can activate a large number of T cells indiscriminately. This unregulated activation induces an excessive immune response, causing a significant release of cytokines, often referred to as a cytokine storm. This overactivation can result in dangerous symptoms such as high fever, low blood pressure, multi-organ failure, and even death. Super antigens are therefore key factors in the severity of certain bacterial infections.