The best answer to this question is c because a chemical change is when the original substance is changed into something else. If you boil water, it is still water. If you melt an ice cube, the water that made the ice cube is still water. Dissolving 10 grams of salt into changes the water and salt into a combined new solution. Splitting water into hydrogen and oxygen still gives you the original substances that made up the water molecule, so there was not any chemical change.
Your answer should be:
C. dissolving 10 grams of salt in water
