Final answer:
Margret displays cultural competence by respecting and accommodating Dione's religious observance when scheduling therapy sessions.
Step-by-step explanation:
Margret's awareness of Dione's Seventh Day Adventist Sabbath and her accommodation to not schedule therapy sessions during that time best illustrates the concept of cultural competence. Cultural competence involves understanding and respecting individuals' cultural beliefs and practices, and then incorporating that understanding into one's professional practice. In this case, Margret demonstrates cultural competence by acknowledging and respecting Dione's religious observance of the Sabbath when scheduling therapy sessions.