[Solved] Which of the following is not a paraphilia that was once treated as "illegal"? A) Masturbation B) Female orgasm C) Homosexuality D) Pornography E) Perihelia Frequency: The number of occurrences of a repeating event per unit of time, often used in the context of waves or vibrations. Wavelength: The distance between two consecutive peaks or troughs in a wave, which determines its color in the spectrum of visible light or its properties in other types of waves. Frequency: Frequency is the number of times a wave completes a cycle of oscillation per unit time, typically measured in hertz (Hz). Wavelength: Wavelength is the distance between consecutive crests of a wave, especially points in a sound wave or electromagnetic wave.