During a Routine Appointment, a Patient with a History of Seizures

During a routine appointment, a patient with a history of seizures is found to have a phenytoin (Dilantin) level of 23 mcg/mL. What concern will the nurse have, if any?

A) The patient is at risk for seizures because the drug level is not at a therapeutic level.
B) The patient's seizures should be under control because this is a therapeutic drug level.
C) The patient's seizures should be under control if she is also taking a second antiepileptic drug.
D) The drug level is at a toxic level, and the dosage needs to be reduced.