What organization was formerly known as the American Association on Mental Retardation (AAMR)?

The American Association on Intellectual and Developmental Disabilities (AAIDD) is the correct answer because it is the organization that changed its name from the American Association on Mental Retardation (AAMR) to more accurately reflect the understanding and terminology surrounding intellectual and developmental disabilities. This change represents a broader and more inclusive approach to the field, recognizing the importance of cultural sensitivity and the evolving language surrounding these disabilities. By adopting the term "intellectual and developmental disabilities," the AAIDD aims to advocate for individuals more effectively and promote awareness, education, and research in the field.

The other organizations listed either do not share a direct connection to the former name of AAMR or represent different entities. They may focus on related topics or advocacy but are not the renaming of the AAMR itself.