The institute of medicine identified which level of government as the central force in public health, bearing primary public sector responsibility for the health of the people?

The correct answer is the state legislature.  

The Institute of medicine has identified state legislature as the central force in public health. The United States comprises 51 state health departments and many local health agencies. Their structure, size, and authority vary, however, they exhibit specific tendencies to address obesity.  

As they are accountable for public health, they can impart several steps themselves and organize efforts with other departments to further health in all the policy domains.  

prism b but im not for sure