Answer:
(D) The pathogen might not be recognized by the host.
This part of defense would likely be affected if the pathogen contained a mutation in it's pathogen-associated molecular patterns (PAMPs).
Step-by-step explanation:
Pathogens are biological agents that cause illness or diseases to its host. Virus, bacteria, fungi are all examples of pathogens.
To protect against infection, body identifies the microorganisms present in it. It does this by identifying the molecules that are different "from the groups of related microorganisms" and are not associated with human cells. These microbial molecules are called 'Pathogen associated molecular pattern or PAMPs'.
If there is a mutation in the PAMP of pathogen, it will not be recognized by the host.