Answer:
C. the olfactory epithelium
Explanation:
According to various studies conducted by medical professionals it can be said that all of the answers provided except for the olfactory epithelium can stop less aggressive pathogens. This is because the olfactory epithelium is a tissue inside the nasal cavity whose only purpose is to send odor signals to the brain, but does not contain anything that can stop less aggressive pathogens.
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