Yes, I am sure. A colloid is indeed defined as a mixture in which one substance (the dispersed phase) is evenly distributed and suspended in another substance (the continuous phase). This fits best with option a. made from one state of matter suspended in another.
To clarify the other options:
- b. a solute is mixed in a solution refers more specifically to a solution, not a colloid.
- c. filled with bubbles and particles is too vague and not accurate in defining a colloid.
- d. a pure substance is incorrect, as a colloid is a mixture, not a pure substance.
If you have further questions or discussions about colloids, feel free to ask!