If I is the intensity of the incident light then R + T = I. Since the incident ray is travelling in a denser medium (glass), it will be totally reflected at a certain critical angle $$\theta$$_c. For $$\theta$$ < $$\theta$$_c a part of the incident intensity is reflected and the remaining part is transmitted. But for $$\theta$$ > $$\theta$$_c, there is no refracted ray. Hence for $$\theta$$ > $$\theta$$_c, the value of R is 100%. Hence the only correct option is (c).