A ray of light falls on the surface of a spherical glass paper weight making an angle \[\alpha \] with the normal and is refracted in the medium at an angle \[\beta \]. The angle of deviation of the emergent ray from the direction of the incident ray [NCERT 1982]

• A.            \[(\alpha -\beta )\]           
• B.            \[2(\alpha -\beta )\]
• C.            \[(\alpha -\beta )/2\]       
• D.            \[(\beta -\alpha )\]