[Solved] Sound waves are simply ___________. A)the vibration of the molecules of the air surrounding us B)the impact of acoustrons in the air C)a form of electronic radiation D)the result of emitted photons from a source Intrapersonal Activity: Activities or processes that occur within the individual's mind. Autoeroticism: The practice of achieving sexual pleasure through stimulation of one's own body. Penial-vaginal Intercourse: A sexual encounter characterized by the penis being inserted into the vagina. Genital Thrusting: A sexual behavior involving the rhythmic motion of the pelvis, often associated with the act of intercourse or sexual excitement.