A ray of light travelling in water falls at right angles to the boundary of a parallel-sided glass block. The ray of light:
is refracted towards the normal
is refracted away from the normal
does not get refracted
is reflected along the same path

(c) does not get refracted

Explanation

When a ray of light travelling in water, falls at right angles (90°) to the boundary of a parallel-sided glass block or travels along with the normal. The ray of light does not get refracted.