You are presented with the question "What causes a root to emerge from an acorn?" and the following answer choices: 
- lipids
 - leaves
 - air
 - water
 - glaciers
 - erosion
 - fungi
 - solutes

Now knowing that the force of water against the seed coat causes a root to emerge from a seed and acorns are the seeds of oak trees, choose the best answer.


 

    water     