What Has Research Found About the Five Stages of Dying

What has research found about the five stages of dying proposed by Elizabeth Kübler-Ross?​

A) ​Only two of the five stages were found to have any true validity.
B) ​The five stages do, in fact, occur in a set sequence across every culture studied.
C) ​The stages all exist, but occur in one set sequence for women and a different set sequence for men.
D) ​The stages should not be viewed as necessarily occurring in a specific sequence.