What involves securing a debtor's property as security or payment for a debt?

The correct answer is C, as a lien is a legal right or interest that a lender has in the borrower's property, granted until the debt obligation is satisfied. This means that if a debtor fails to fulfill their payment obligations, the lien allows the creditor to seize the specified property as a means of securing payment for the debt.

In the context of health insurance billing, liens can be a crucial aspect when dealing with claims and payments, particularly in scenarios such as personal injury cases, where medical providers may place a lien on future settlements to ensure they receive payment for the services rendered to the injured party.

Subrogation refers to the process by which an insurance company seeks reimbursement from another party that is responsible for a loss. Outsourcing involves delegating certain business processes to third-party providers and does not pertain to securing debts. A subpoena is a legal document that orders an individual to appear in court or provide evidence, which is unrelated to debts or property security.