Answer :
Refractive index tell us about the speed of light in medium with respect to the speed of light in vacuum.
Formula for refractive index is,
[tex]\begin{gathered} n=\frac{C}{V} \\ Where, \\ n=Refractive\text{ }index \\ C=Speed\text{ }of\text{ }light\text{ }in\text{ }vacuum \\ V=Speed\text{ }of\text{ }light\text{ }in\text{ }medium \end{gathered}[/tex]So,
[tex]V=\frac{C}{n}=\frac{3\times10^8}{1.95}=1.538\times10^8m\text{/s}[/tex]The speed of light in medium = 1.54 x 10^8 m/s.
So option A is correct of option.