"which organization provided services to the poor?
tammany hall
board of health
tenement house
hull house

"

BOARD OF HEALTH

Explanation:

Boards of Health are organization thati is made up of people from every walk of life who care about the well being of their community and provide health service to the poor. They are elected or appointed to a term of office and are given the legal authority to set policies and make regulations to protect the public and environmental health.

an informal structure in a bureaucracy would be something like so-called "office politics". where there's a formal structure set up for the organization, but then an informal subculture as well that has a way of organizing the bureaucracy further. this can be positive because it sets up an added degree of organization, albeit informal, within the bureaucracy.