Final answer:
The statement 'These individuals host the pathogen and transmit the infection' describes infected individuals in the S-I-R model, who are capable of spreading the disease to others. Option 2 is correct.
Step-by-step explanation:
In the S-I-R model, which represents the dynamics of an infectious disease in a population, infected individuals are those who host the pathogen and transmit the infection.
Therefore, in the given question, the statement "These individuals host the pathogen and transmit the infection" corresponds to infected individuals (option 2).
Susceptible individuals (option 1) are those who have not yet been infected but are vulnerable to becoming infected. Recovered individuals (option 3) are those who have been infected in the past and have either developed immunity to the pathogen or are no longer infectious.
In the S-I-R model, the statement 'These individuals host the pathogen and transmit the infection' describes the outcome over time of infected individuals. Infected individuals have the pathogen in their bodies and can spread the infection to others.