Final answer:
The phrase "to pay back" means to return borrowed money, as in repaying a loan to a friend or a financial institution.
Step-by-step explanation:
The phrase "to pay back" means option B) To return borrowed money. When someone pays back money, they are giving back the money they previously borrowed, typically from a person or a financial institution. This term is often used in financial transactions and personal relationships where there has been a loan or monetary advancement that is expected to be returned, sometimes with added interest depending on the agreement.
The process of paying back can involve a single payment or a series of payments over time. For example, if you borrow $50 from a friend, paying them back would mean giving them the $50 you owe. Similarly, if you take out a bank loan, you repay the loan amount plus any interest in monthly installments until the debt is fully paid.