How much space does a plant need to grow? How much soil does a plant need to grow? How much water will make a plant grow tallest? How much sunlight will make a plant grow tallest?
I gave my students this multiple choice question: Three identical seeds are planted and grown in identical pots of soil. All three pots receive equal amounts of sunlight. The plants are watered once each day. Plant A is given 10 milliliters (mL) of water. Plant B is given 20 mL of water. Plant C is given 30 mL of water. The height of each plant is measured and recorded after ten days. Which question could be answered by this experiment?

Only one answer is correct among these 4 choices:
- How much space does a plant need to grow?
- How much soil does a plant need to grow?
- How much water will make a plant grow tallest?
- How much sunlight will make a plant grow tallest?

Could you tell me which one is correct?

How much water will make a plant grow tallest?