Which of the following best describes the main role of regulatory T cells in the context of the human microbiome?

• A. They enhance the body's response to foreign pathogens.
• B. They directly attack pathogens found within the microbiome.
• C. They protect against autoimmunity by moderating the immune response to the microbiome.
• D. They are responsible for the digestion of complex carbohydrates.

Answer: (C)