Which of following is correct regarding the explanation for transgenderism?
it is strictly biological and associated with chemical imbalances in the brain.
it is a behavior that is learned through socializing with other transgender individuals.
it is genetic and usually skips one generation.
currently, there is no definitive explanation for transgenderism.

It is strictly biological and associated with chemical imbalances in the brain.

Explanation:

In years 1995 and 2000, a part in the brain of trans and cisgender men and women was examined by a group of researchers. This part is called the "bed nucleus of the stria terminalis" (BSTc), and was found that it is bigger and contains more cells in men than in women. It is a significant sexual dimorphism and the reasons behind this are unknown; it determines if a brain is "female" or "female". Therefore, in transgender people, the BTSc genetic conditions are what affect gender identity, as for them, it differs from their biological sex.

the 2nd option is the answer