Which of the following statements is true regarding gender identity disorder? A

Which of the following statements is true regarding gender identity disorder?
A) It is a common disorder first displayed in adolescence by those who are not sure of their sexual orientation.
B) Studies show this disorder is largely caused by environmental factors.
C) Those diagnosed with this disorder are satisfied by simply dressing in clothes of the opposite sex.
D) It can become so complex and difficult to deal with that the individual, as an adult, may undergo sex-reassignment surgery.
E) It usually does not surface until middle adulthood, typically after a sexual trauma.