[Solved] Physical activity A) contributes about 70 percent of total energy expenditure. B) is only counted as a significant contributor if it is a formal, regular exercise program. C) includes daily activities as seemingly insignificant as fidgeting. D) contributes very little to overall energy expenditure. Havelock Ellis: A pioneering British sexologist and author known for his studies and writings on human sexuality in the late 19th and early 20th centuries. Masturbation: The act of self-stimulation of one's own genitalia, frequently leading to climax. Krafft-Ebing: refers to Richard von Krafft-Ebing, a 19th-century psychiatrist and author known for his research in human sexuality. Human Sexuality: An area of study and aspect of human life that encompasses sex, gender identities and roles, sexual orientation, eroticism, pleasure, intimacy, and reproduction.