meter stick, spring scale balance, stopwatch balance, meter stick meter stick, stopwatch
I gave my students this multiple choice question: Which tools are needed to measure the effects of friction on a block of wood?

Only one answer is correct among these 4 choices:
- meter stick, spring scale
- balance, stopwatch
- balance, meter stick
- meter stick, stopwatch

Could you tell me which one is correct?

meter stick, spring scale