39.To visualize a virus with a diameter of approximately 20 nm, a researcher uses a transmission electron microscope. Electrons are accelerated from rest through a potential difference V, acquiring a non-relativistic kinetic energy K= eV. According to the de Broglie relation, how do the electron wavelength and the microscope's resolution change if the accelerating voltage is increased to four times its original valuе? (A) The wavelength doubles; resolution becomes worse. (B) The wavelength is halved; resolution becomes better. (C) The wavelength decreases by a factor of 4; resolution becomes better. (D) The wavelength increases by a factor of ; resolution becomes worse. (E) The wavelength decreases by a factor of 2; the resolution decreases by a factor of 2.