Which of the following debts is considered secured?

A secured debt refers to a type of loan that is backed by collateral, which means that the lender has a claim on specific assets if the borrower fails to repay. In the case of mortgage loans, the property itself serves as the collateral. If the borrower defaults on the loan, the lender has the right to foreclose on the property and recover the remaining balance owed by selling the asset.

The other types of debts listed do not involve collateral; credit card debt is typically unsecured, as it is not backed by any specific asset. Child support payments are also not tied to any collateral but are considered a legal obligation. Income tax liabilities are treated as unsecured debts as well, meaning that the government does not have a specific asset as collateral but can pursue collections through other means. Therefore, the nature of a mortgage loan being backed by the property makes it the correct answer as a secured debt.