Answer:
The correct answer would be - c. A solid was added to water and the mixture was stirred until the solid was no longer visible
Explanation:
Photostabalizing is the process where a solid change its color in the presence of ultraviolet light, it is a chemical change, so the first option would not be the correct answer.
when two liquid or aqueous solutions are mixed together and form a solid substance, this reaction is known as precipitation and it is a chemical reaction too.
When a solid is placed in a liquid and after stirring it makes the solid vanish is a physical change known as dissolving character.
Thus, the correct answer is option C.