Which of the following wave types has a wavelength closest to visible light? gamma rays, infrared rays, radio, or microwaves

That would be the corect answer hope this

Answer(a)   the matererials that are in contact, the two materials and the nature of their surfaces/// (b)/// the force pushing the two surfaces together, pushing the surfaces together causes the more of the asperities to come together and increases the surface area in contact with each other