This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
Roopmati, A 56–year–old female with lymph-node-positive breast cancer was treated with systemic chemotherapy. Four weeks later, she developed frequent urination, suprapubic pain, dysuria, and hematuria. Which of the following could have prevented this patient's condition? 
Select and explain. 
A. Folinic acid, B. Mesna, C. Dexrazoxane, D. Amifostine
B: Mesna
Answer: B: Mesna 
Explanation: None