Which of the following statements is true?

A) A patient's account number is always the same as his or her patient ID.
B) A patient must be the guarantor of his or her own account with a healthcare provider.
C) A guarantor is a person who is responsible for paying any portion of a healthcare bill that is not covered by insurance.
D) A patient cannot be the beneficiary of a health plan unless he or she is also the policy holder.

C