When a ray of light passes from one medium to another medium, refraction takes place when angle of incidence is

45 , if ray is travelling from lighter to denser medium then after refraction it bend towards the normal between the surfaces.

(a) If angle of incident is 0. Then the ray will go on its own path it will not show any deflection . so there is no refraction.

SEE the figure below to get an idea how ray will travel when angle of incident is zero.

So this option is incorrect

(c)As angle of incident is 90 , there is also no refraction.