5.A 67-year-old man with metastatic colon cancer is being treated with FOLFOX (5-FU, leucovorin, oxaliplatin) and complains of severe numbness/tingling in his extremities during cycle 3 when touching anything cold. What agent is causing these symptoms?

A. 5-FU

B. Leucovorin

C. Oxaliplatin

D. Ondansetron

E. Compazine