a
In optics, Lambert's cosine law says that the radiant intensity or luminous intensity observed from an ideal diffusely reflecting surface or ideal diffuse radiator is directly proportional to the cosine of the angle \(\theta\) between the direction of the incident light and the surface normal.

In optics, Malus's Law states that the intensity of a beam of plane-polarized light after passing through a rotatable polarizer varies as the square of the cosine of the angle through which the polarizer is rotated from the position that gives maximum intensity.

In optics, Bragg's law, or Wulff-Bragg's condition, a special case of Laue diffraction, gives the angles for coherent and incoherent scattering from a crystal lattice. When \(X\)-rays are incident on an atom, they make the electronic cloud move, as does any electromagnetic wave.

Brewster's law gives relationship for light waves stating that the maximum polarization (vibration in one plane only) of a ray of light may be achieved by letting the ray fall on a surface of a transparent medium in such a way that the refracted ray makes an angle of \(90^{\circ}\) with the reflected ray. So, the correct answer is option (A), i.e Brewster's Law.