The phenomenon of bending of light rays as they pass from one transparent medium to another is called:
Correct: B
Refraction is the phenomenon where light changes its direction of propagation (bends) as it passes obliquely from one transparent medium to another, due to a change in its speed. Reflection is the bouncing back of light, dispersion is the splitting of light into its constituent colours, and diffraction is the bending of light around obstacles or through small apertures.