If \[\hat{i}\] denotes a unit vector along incident light ray, \[\hat{r}\] a unit vector along refracted ray into a medium of refractive index \[\mu \] and \[\hat{n}\] unit vector normal to boundary of medium directed towards incident medium, then law of refraction is [EAMCET (Engg.) 1995]

• A.            \[\hat{i}\,.\,\hat{n}=\mu (\hat{r}\,.\,\hat{n})\]                         
• B.            \[\hat{i}\times \hat{n}=\mu (\hat{n}\times \hat{r})\]
• C.            \[\hat{i}\times \hat{n}=\mu (\hat{r}\times \hat{n})\]        
• D.            \[\mu (\hat{i}\times \hat{n})=\hat{r}\times \hat{n}\]