The correct answer is A) make it easier for them to pay down their debts.
Farmers supported free coinage of silver because they believed it would make it easier for them to pay down their debts.
In the 1880s, what US farmers thought was that if they supported unlimited coinage of silver it should lead to higher prices for farm products. If they could earn a better income for selling their products, then it would be easier for them to pay their debts. SO they thought that was the best decision to make.