An Index of Refraction Less Than One for a Medium

Multiple Choice

An index of refraction less than one for a medium would imply

A) that the speed of light in the medium is the same as the speed of light in vacuum.
B) that the speed of light in the medium is greater than the speed of light in vacuum.
C) that the speed of light in the medium is less than the speed of light in vacuum.
D) refraction is not possible.
E) reflection is not possible.