The correct statement is 1. Inflation benefits the debtors becoz inflation causes the purchasing power of money to decline, hence in real terms value of debt declines.
For ex: let a farmer borrows $10 to buy seeds of a plant hoping to make $20 out of that crop. Inflation kicks in and the farmer sells & harvests the crop for $50(instead of the expected $20). then instead of paying half of his income to pay the debt he only pays one-fifth of his income. So it is the debtor who eventually gets benefitted by inflation.