Are dogs better pets than cats?. Are dogs happy when they are walked?. Are cats more active at night than during the day?. Are cats easier to take care of than dogs?.
I gave my students this multiple choice question: Which of the following questions is testable in a scientific investigation?

Only one answer is correct among these 4 choices:
- Are dogs better pets than cats?.
- Are dogs happy when they are walked?.
- Are cats more active at night than during the day?.
- Are cats easier to take care of than dogs?.

Could you tell me which one is correct?

Are cats more active at night than during the day?.