The main lesson Brym and Lie draw from the story of baby Brenda is that:

A) biology is destiny
B) biology establishes most of gender identity and society helps a little
C) sex is organized around biological factors
D) gender identity does not exist
E) social learning of gender begins very early in life

The main lesson Brym and Lie draw from the story of baby Brenda is that social learning of gender begins very early in life. This is evident from the fact that despite being raised as a girl, Brenda did not identify with the gender assigned to her at birth and eventually transitioned to living as a male named David. Therefore, even though biology does play a role in determining sex, socialization and learning of gender roles and expectations have a significant impact on one's gender identity.