Choose the correct option for the following Assertion (A) and Reason (R).

Assertion

When the accelerating potential of an electron beam used in a crystal-diffraction experiment is increased, the diffraction angles for the same crystal planes and diffraction order generally shift toward smaller values.

Reason

Increasing the accelerating potential increases the electron momentum and therefore decreases its de Broglie wavelength; for fixed crystal spacing and diffraction order, Bragg's law then requires a smaller value of sinθ.