Correct answer choice is:
D. Reservoir.
Explanation:
Further particularly, transmission transpires when the operator vacates its reservoir or host by a portal of an outlet, is carried by some convention of transmission and penetrates through a suitable portal of entry to contaminate a responsive host. This sequence is seldom called the chain of infection.
There are six links in the chain transmission, which includes:
- The infectious agent
- Reservoir
- Portal of exit
- Mode of transmission
- Portal of entry
- Susceptible host.
