What Is the Most Likely Reason the Real-Life Experience Part

What is the most likely reason the real-life experience part of sexual reassignment is done before the surgery?

A) To be sure the person understands the risks of surgery
B) To be sure the person can be comfortable living as the opposite sex
C) To show the person that gender transition is ill-advised and dangerous
D) To show the person that gender transition can be done without surgery
E) To encourage the person to back out of the surgery