Answer: The correct answer is that she paid interest on the money that she borrowed.
Explanation: When a customer borrows money to purchase an item there is normally a cost involved. The extra money that she paid is the interest, which is the cost of the bank loaning her money. This money is the bank’s income on loaning her the money.
The bank may use it for paying interest to customers who have money deposited in the bank, for their expenses or for profits for their shareholders.