Final answer:
The nurse should monitor for increased blood pressure as a potential adverse effect of duloxetine, which is used to treat diabetic neuropathy pain.
Step-by-step explanation:
A nurse monitoring a client who is taking duloxetine for treating diabetic neuropathy pain should be aware of potential adverse effects of the medication. Among the options provided, the nurse should monitor for A) Increased blood pressure as a potential adverse effect. Duloxetine can cause hypertension as a side effect in some patients. While other side effects like hypoglycemia, confusion, and bradycardia are also possible with various medications, increased blood pressure is more commonly associated with duloxetine, particularly at higher doses or among patients with a predisposition to hypertension.