How do pathogen-associated molecular patterns (PAMPs) contribute to the innate immune response?

• A. They are unique to each pathogen and help the immune system remember past infections.
• B. They are specific to viruses and help in the production of antibodies.
• C. They are produced by the host cells to signal the presence of pathogens.
• D. They are recognized by pattern recognition receptors, triggering an immune response.

Answer: (D)