Answer:
The mucus is the exit portal.
Explanation:
To understand the relationships between the different elements that lead to the onset of a communicable disease, the traditional scheme is called the epidemiological chain, also known as the chain of infection.
The chain of infection is divided into three components: the causal agent, the reservoir and the exit port.
In the case of the above question, the causative agent is the cold virus, the reservoir is JoAnn, and the exit port is mucus that JoAnn is expelling.
The path by which an infectious agent leaves its host is generally referred to as the exit door.
