Refractive index of media A, B, C and D are
A 1.33
B  1.52
C  1.44
D 1.65
In which of the four media is the speed of light (i) maximum and (ii) minimum?

Refractive index of a medium is inversely proportional to the speed of light in that medium.

(i) Speed of light is maximum in medium A for which n (= 1.33) is minimum.

(ii) Speed of light is minimum in medium D for which n (= 1.65) is maximum.

n is the refractive index.