Answer:
the last answer seems to be correct
Explanation:
How do farmers contribute to water pollution?
One big reason is the chemicals that they used to be able to let their plant grow well. The water that they use in irrigation sometimes they uses chemicals to it. Farmers also throw chemical wastes to water without thinking the result of this.
A disadvantage of using a sentence outline instead of a topic outline is that a sentence outline is often time-consuming.
Hope this helps!