C. A small INAH-3 is associated with a female gender identity in humans. Studies have suggested that there may be differences in brain structure between individuals with different gender identities. One of the most studied regions of the brain in this regard is the hypothalamus, specifically a region called the interstitial nucleus of the anterior hypothalamus (INAH). INAH-3 is a subregion of the hypothalamus that has been found to be sexually dimorphic, meaning that it is larger in males than in females. However, studies have also found that the volume of INAH-3 is smaller in transgender women (individuals assigned male at birth but identify as female) compared to cisgender men (individuals assigned male at birth and identify as male), suggesting that this region may play a role in gender identity.