sugar added to soda detergent added to water lemon juice added to milk salt added to water
I gave my students this multiple choice question: Which of the following causes a chemical change?

Only one answer is correct among these 4 choices:
- sugar added to soda
- detergent added to water
- lemon juice added to milk
- salt added to water

Could you tell me which one is correct?

lemon juice added to milk