An individual's internal sense of being male or female is the definition of what?

The correct answer, gender expression/identity, refers to an individual's deeply held understanding of their own gender, which can align with traditional definitions of male and female, or fall outside of those categories altogether. This internal sense is crucial to how a person perceives themselves and how they relate to others in terms of gender.

Gender identity is an intrinsic aspect of a person's self-concept and encompasses the feelings and identity they hold regarding their gender. This can involve a range of experiences and expressions that may or may not align with societal expectations based on one's sex assigned at birth.

The other options pertain to different aspects of gender. Gender affiliation relates to the group or community a person identifies with but does not capture the individual sense of self. Gender representation concerns how gender is depicted or portrayed in society, which is more about external perceptions rather than internal identity. Gender reassignment specifically refers to the medical and social transition process that individuals may pursue to align their physical bodies with their gender identity, rather than the identity itself.