A nurse is monitoring a 6-month-old infant 20 minutes after administering a hepatitis B immunization.Which of the following findings is the nurse's priority?

Choice A rationaleProlonged crying is commonly associated with the discomfort of the injection but does not indicate an acute allergic reaction. It generally subsides with comfort measures and is not a priority finding.Choice B rationaleRedness at the injection site is a localized inflammatory response, expected after immunization, and it does not suggest a systemic reaction.Choice C rationaleHives on the neck may indicate an allergic reaction, potentially leading to anaphylaxis. This immune response warrants immediate intervention to prevent airway obstruction or systemic complications.Choice D rationaleA temperature of 37.7°C (99.9°F) is a mild fever, a normal post-immunization reaction, reflecting the body's immune response to the vaccine rather than an urgent concern.