human
Question: A student wants to create a model showing the most important reason why old gasoline should never be poured into the soil. Which of the following must be included in the model?

Choices:
A) gasoline evaporating from soil
B) gasoline catching fire in the soil
C) gasoline polluting an old septic system
D) gasoline trickling down into groundwater
gpt
The correct answer is 3: gasoline trickling down into groundwater.