Answer: Option D
Explanation:
Once the pathogen enters the body, it starts dividing and after a certain period of time the patients experience some sign and symptoms of illness.
The prodromal period occurs just after the incubation period. In this phase the pathogen keeps on dividing and the host begins to experience general symptoms and signs of illness.
This is a result of the activation of immune system of the body which results in the swelling, pain, soreness.
