Which of the following is most defensibly classified as an 'elimination' control on the hierarchy of controls, in the context of infectious disease prevention?

Among the choices, achieving population-level immunity through an effective vaccine is the option most often discussed as approaching true 'elimination' of an infectious hazard (since widespread immunization can functionally eliminate the disease's ability to spread, as historically achieved with smallpox) — though note that for a single individual, a vaccine is sometimes alternatively framed as risk reduction rather than literal hazard elimination, since the pathogen itself still exists in the environment.