They grow toward light. They grow toward surface warmth. They grow opposite the direction of the bedrock. They grow opposite the direction of the pull of gravity.
I gave my students this multiple choice question: How do the sprouts of seeds buried in complete dark in the soil find their way to the surface of the soil?

Only one answer is correct among these 4 choices:
- They grow toward light.
- They grow toward surface warmth.
- They grow opposite the direction of the bedrock.
- They grow opposite the direction of the pull of gravity.

Could you tell me which one is correct?

They grow opposite the direction of the pull of gravity.