Which theoretical orientation is most in understanding the origin of gender identity disorder?

The answer is "biological".

Gender identity disorder or for short GID is also known as “Gender dysphoria”, this is the trouble a man encounters because of the sex and gender identity they were allotted during childbirth. A man with dysphoria regularly encounters significant uneasiness and disappointment with life, trailed by gloom, nervousness and disturbance.

answer; (you have the right of way);