A nurse in a provider's office is caring for a client who is at 34 weeks of gestation and at risk for placental abruption. The nurse should recognize that which of the following is the most common risk factor for abruption?

A. Hypertension (chronic or pregnancy-induced) is the most common risk factor for placental abruption. High blood pressure can cause vascular changes in the placenta, increasing the risk of premature separation. B. Blunt force trauma (e.g., from a car accident) can cause abruptions but is less common than hypertension. C. Cigarette smoking slightly increases risk but is not the leading factor. Smoking contributes to placental vascular insufficiency over time. D. Cocaine use is a significant risk factor because it causes vasoconstriction, but it is less prevalent than hypertension as a cause of abruption.