Which of the following is/are illustration(s) of Refraction of light?

Refraction of light: The phenomenon of change in direction of propagation of light at the boundary when it passes from one medium to other medium is called refraction of light.

Some Illustrations of Refraction:

1. Bending of a linear object when it is partially dipped in a liquid inclined to the surface of the liquid.

2. Twinkling of stars.

3. Oval shape of sun in the morning and evening.

4. An object in a denser medium when seen from a rarer medium appears to be at a smaller distance.