A mother calls the pediatrician's office stating that her 15-month-old son received an MMR vaccination yesterday. Today, the site of the injection is red, warm, and puffy. What is the best action for the nurse to take?

A Report the symptoms to the physician as an adverse reaction C Advise the mother to give her son baby aspirin D Explain to the mother that this is an expected response B Suggest the mother apply a warm compress every two hours