Final answer:
The distinction between Bridget being bisexual and Kale being heterosexual exemplifies 'sexual orientation,' a central part of one's identity describing who they are attracted to.
Step-by-step explanation:
The example of Bridget who is bisexual and Kale who is heterosexual illustrates the concept of sexual orientation, which refers to an individual’s physical, mental, emotional, and sexual attraction to a particular sex or sexes. Sexual orientation is a distinct aspect of a person's identity and is acknowledged in various forms, such as heterosexuality, homosexuality, bisexuality, pansexuality, and asexuality, among others. It is important to recognize that these orientations exist on a spectrum, with many people identifying with terms that describe their unique experience of attraction.