A laser beam travels from glass into air and strikes normally the smooth interface between the two media. In the air
(a) the light travels with a lower speed normally to the interface;
(b) the light travels with a higher speed normally to the interface;
(c) the light travels with unchanged speed but bends away from the normal;
(d) the light travels with a higher speed and bends away from the normal;
(e) the light travels with a lower speed and bends away from the normal.