This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other topics and Adverse effects, Subject name: Anatomy
Most common side effect of 5-fluorouracil us 
Select and explain. 
A. G.I toxicity, B. Bone marrow depression, C. Neurotoxicity, D. Cardiotoxicity
A: G.I toxicity
Answer: A: G.I toxicity 
Explanation: Ref-KDT 6/e p824 Diarrhea most common adverse effect of 5-FU It can also cause hand and foot syndrome and bone marrow suppression