Let the refractive index of a denser medium with respect to a rare medium be N₁₂ and its critical angleθC. At an angle of incidence A when light is travelling from denser medium to rarer medium, a part of the light is reflected and the rest is refracted and the angle between reflected and refracted rays is 90∘. Angle A is given by:
(A) tan⁻¹(sinθC)
(B) 1/tan⁻¹(sinθC)
(C) 1/cos⁻¹(sinθC)
(D) cos⁻¹(sinθC)