The Nurse in Charge of a Clinical Study Welcomes the Participants

The nurse in charge of a clinical study welcomes the participants in an open forum.One client is surprised that there are men and women from several ethnic groups.The nurse tells the group that in the past,ethnic variables were largely unknown or ignored for which reasons?
Select all that apply.

A) Clinical trials failed to include ethnically diverse subjects.
B) Clinical trials comprised mostly Caucasian males.
C) Little attention was focused on identifying the different effects drugs had on various ethnic groups.
D) Research proved there were no differences among ethnic groups.
E) The large majority of clinical trials included Caucasian females.