Final answer:
The nurse should discontinue the medication and notify the provider.
Step-by-step explanation:
The correct intervention for the nurse to take in this situation would be c) Discontinue the medication and notify the provider. Urticaria, also known as hives, is an allergic reaction that can be caused by medications. In this case, the client's urticaria is likely a result of the oral amoxicillin and clavulanate potassium. It is important for the nurse to stop the medication and inform the provider, as this could indicate a drug allergy or hypersensitivity.