Regarding Gender Variance and Gender Dysphoria, Which of the Following

Regarding gender variance and gender dysphoria, which of the following statements is\are TRUE?

A) Gender variance, or transsexualism, was once considered a psychiatric illness.
B) An individual usually is considered for a diagnosis of gender dysphoria only if he\she is experiencing extreme distress as a consequence of his\her gender variance.
C) Treatment for gender dysphoria may include psychotherapy and, in more dramatic cases, sex reassignment surgery may be undertaken.
D) All of these statements are true.