These are all true but I do not know the last part of the answer
<span>The chain of infection, if we think of it as an actual chain, is made up of six different links: pathogen (infectious agent), reservoir, portal of exit, means of transmission, portal of entry, and the new host. Each link has a unique role in the chain, and each can be interrupted, or broken, through various means
a-infectious agent
b-portal of entry
c-portal of exit
d-reservoirs</span>
I can’t see the whole question but would love to help :)
