What Was a Major Impetus for the Support of Deinstitutionalization

What was a major impetus for the support of deinstitutionalization?

A) The funding for community programs, which made it possible for mental patients to be treated in a less restrictive environment closer to their homes
B) The cases of Rennie v. Klein (1978) and Rogers v. Okin (1979)
C) The passing of the "Guidelines on Multicultural Education, Training, Research, Practice, and Organizational Change for Psychologists" by the American Psychological Association (2003)
D) The notion that many mental hospitals were primarily "warehouses for the insane" that provided little benefit to patients