Which of the following definitions best describes the role of pathogen-associated molecular patterns (PAMP's)?

A)PAMP's are molecules on a pathogen that can be recognized by the host organisms immune system.
B)PAMP's are molecules on a host cell that can be recognized by the pathogen's attack system.
C)PAMP's are molecules on the host immune system that cause it to attack itself as in autoimmune disorders.
D)PAMP's are molecules on a pathogen that can be recognized by other pathogens so they can exchange genetic material with each other.