[Solved] What is the most common language group in Central Asia, based on the number of native speakers? A)Farsi B)Indo-European C)Mongolian D)Tibetan E)Turkic 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.