Final answer:
Recovered individuals in the S-I-R model are those who have acquired immunity and are therefore resistant to future infections of the same pathogen, due to the development of immunological memory.
Step-by-step explanation:
The statement 'These individuals acquire immunity through resistance and remain immune to any future infections' describes the outcome over time of recovered individuals in the S-I-R (Susceptible-Infected-Recovered) model. After the period of illness, individuals enter a period of decline, during which the immune response to the pathogen is strong, yielding immunological memory. Immunological memory ensures that upon re-exposure to the same pathogen, the body's secondary adaptive immune response is quicker and more effective, often eliminating the pathogen before it can cause significant damage or symptoms. This is a form of active immunity, resulting from the formation of memory cells, which renders individuals resistant to future infections by the same pathogen. Meanwhile, herd immunity protects even those who have not been infected or who are still susceptible by reducing the overall number of people who can transmit the disease.