A 23-year-old woman with bone marrow failure is treated with a large dose of rabbit antithymocyte globulin. Ten days later, she develops fever, lymphadenopathy, arthralgias, and erythema on her hands and feet. Which of the following is the most likely cause of these symptoms?

A) Type III hypersensitivity reaction
B) Cytokine release syndrome
C) Serum sickness
D) Acute hemolytic reaction