a sharp knife a magnifying glass a long piece of string a large jar with air holes in the top
I gave my students this multiple choice question: Which tool would be the most helpful in an investigation of the life cycle of a monarch butterfly?

Only one answer is correct among these 4 choices:
- a sharp knife
- a magnifying glass
- a long piece of string
- a large jar with air holes in the top

Could you tell me which one is correct?

a large jar with air holes in the top