During a Blood Transfusion, the Patient Begins to Have Chills

During a blood transfusion, the patient begins to have chills and back pain. What is the nurse's priority action?

A) Observe for other symptoms.
B) Slow the infusion rate of the blood.
C) Discontinue the infusion immediately, and notify the prescriber.
D) Tell the patient that these symptoms are a normal reaction to the blood product.