A nurse is preparing to administer the initial dose of penicillin G IM to a client. The nurse should monitor for which of the following as an indication of an allergic reaction following the injection?

The correct answer is C: Urticaria. Urticaria, also known as hives, is a common symptom of an allergic reaction to penicillin. It presents as raised, red, itchy welts on the skin. This occurs due to the release of histamine in response to the allergen. Pallor (A) is not typically associated with an allergic reaction. Bradycardia (B) refers to a slow heart rate and is not a common sign of an allergic reaction. Dyspepsia (D) is indigestion and is not a typical symptom of an allergic reaction to penicillin.