What "Lesson" Was Learned Through the Life and Death of Money's

What "lesson" was learned through the life and death of Money's sex-reassignment patient Bruce/Brenda/David?

A) Life as a female is much easier than life as a male
B) Gender identity may not be as pliable as once thought
C) Reassigning sex prior to age 2 has little impact on later self-conceptions of gender
D) Any surgical procedure may result in potentially deadly medical complications