Final answer:
The subject of this question is Epidemiology, which involves studying the distribution and determinants of health-related events in populations.
Step-by-step explanation:
The subject of this question is Epidemiology.
Epidemiology is the study of the distribution and determinants of health-related events, such as diseases, in populations. It involves investigating the prevalence and incidence of diseases, as well as the factors that contribute to their spread and impact.
In this scenario, the question is asking about the infection rate and the number of susceptible and infected students, which are concepts that fall under the field of epidemiology.