Final answer:
The five-stage model of dying was developed by Elizabeth Kubler-Ross, who observed that the process of dying involves denial, anger, bargaining, depression, and acceptance. Her work was a major contribution to the study of death and dying.
Step-by-step explanation:
The five-stage model of dying was developed by Elizabeth Kubler-Ross. She observed that the process of dying had five distinct stages: denial, anger, bargaining, depression, and acceptance. These stages may occur in different orders and not everyone experiences all of them. Her work was a major contribution to the systematic study of death and dying.