You are presented with the question "Water can flow easily through soil where what has formed and expanded?" and the following answer choices: 
- bogs
 - rock
 - Sand
 - ice
 - moss
 - dam
 - peat
 - stem

Now knowing that if soil is permeable then water easily flows through that soil and the increase in permeability is caused by the formation and expansion of ice in the soil, choose the best answer.


 

    ice     