Explanation:

- A mirror is associated with reflection. When light hits a mirror, it reflects back.

- A prism is related to dispersion. When light passes through a prism, it disperses into its component colors.

- Reflection is not relevant to a prism since it primarily reflects light like a mirror.

- Scattering occurs when particles cause light to spread in different directions. It doesn't specifically relate to how a prism works.

- Inversion is the flipping of images or structures, not primarily associated with a prism’s function.

- Dispersion accurately describes the process of splitting light into colors via a prism.

Therefore, the correct answer is: Option 4 - Dispersion