Christopher came down with chicken pox after spending time in his child’s day care. the chicken pox represents what link in the chain of transmission in this scenario?

The correct answer is- Infectious agent

Explanation:

Chickenpox is a very infectious agent that can easily be spread from person to person by coming contact with the virus present on the infected person or its belongings. It is caused by the varicella-zoster virus. Normally it occurs in children but adults can also get affected.

Red rashes with itchy blister are formed on skin in this infection and over the time the blister leaks which contain infectious virus. After 10-21 days of incubation, symptom appears and normally the patient recovers itself within 2 weeks.  

So Christopher might get chickenpox from coming contact with the infected child during spending time in his child daycare so here chickenpox represent the link of infectious agent.