* Light Bending Away from the Normal: When a ray of light travels from a denser medium to a less dense medium, it bends away from the normal (an imaginary line perpendicular to the surface).

* Optically Denser: An optically denser medium is one where light travels slower. This is because the light interacts more with the particles in the denser medium.

Therefore, in this scenario, Medium A is optically denser than Medium B.

Here's why:

* The light ray bends away from the normal, indicating it's moving from a denser to a less dense medium.

* Since the light is bending away from the normal when going from A to B, this means A is the denser medium and B is the less dense medium.