Which best describes reflection and refraction? in both reflection and refraction, rays pass through a boundary. in both reflection and refraction, rays bounce off a boundary. in reflection, rays bounce off a boundary, and in refraction, rays pass through a boundary. in refraction, rays bounce off a boundary, and in reflection, rays pass through a boundary.

The correct option is (C) " In reflection, rays bounce off a boundary, and in refraction, rays pass through a boundary".

Explanation :  

Reflection of light is the phenomenon in which rays bounce off a boundary. The process of reflection is true in the case of light as well as sound waves.

Refraction is the phenomenon in which rays pass through a boundary or the interface. The rays travel from one medium to another of different densities.

So, the correct option is (C) "In reflection, rays bounce off a boundary, and in refraction, rays pass through a boundary".     

a and b sometimes have a positive value

1/0.14nm = 10^10/1.4 a lot