The nurse is monitoring the aPTT level for an assigned client. Which of the following medications requires this type of laboratory monitoring?

A. Clopidogrel is an antiplatelet medication and does not require aPTT monitoring. B. Warfarin requires monitoring of the INR, not aPTT. C. Enoxaparin, a low-molecular-weight heparin, generally does not require aPTT monitoring. D. Heparin therapy requires monitoring of the activated partial thromboplastin time (aPTT) to ensure therapeutic levels and to adjust dosage as necessary.