[Solved] The environmental setting to which a species is adapted is its A)adaptive radiation. B)geographic isolation. C)geographic barrier. D)geological time. E)ecological niche. Sexual Activity: Behaviors associated with the expression of sexuality and erotic desire, including intercourse and other forms of physical intimacy between individuals. Adolescence: The transitional stage of physical and psychological development that generally occurs during the period from puberty to legal adulthood. Homosexual Orientation: A sexual orientation characterized by a romantic or sexual attraction to individuals of the same sex. Sexual Relationships: Interactions between individuals that involve sexual intimacy or activities.