A ray of light in incidentin medium 1 on a surface that separates medium 1 from medium 2 . Let `v_(1) and v_(2)` represent the velocity of light in medium 1 and medium 2 respectively . Also let `n_(12) and n_(21)` represent the refractive index of medium 1 with respect to medium 2 and refractive index of medium 2 with respect to medium 1, respectively. if 1 and r denote the angle of incidence and angle fo refraction, then -

Options

A. `sin1/sin2=n_21=(v_1) /(v_2) `
B. `sin1/sin2=n_21=(v_2) /(v_1) `
C. `sini/sinr=n_12=(v_1) /(v_2) `
D. `sini/sinr=n_12=(v_2) /(v_1) `