This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Wilms Tumor, Subject name: Pathology
In Wilm's tumor the following leads to emergence of resistance to chemotherapy: 
Select and explain. 
A. Nephrogenic rests, B. Monophasic morphology, C. Anaplasia, D. Capsular infiltration
C: Anaplasia
Answer: C: Anaplasia 
Explanation: Wilm's tumor : 5% of tumors reveal anaplasia- Large, hyperchromatic, pleomorphic nuclei and abnormal mitoses . The presence of anaplasia correlates with underlying p53 mutation -Emergence of resistance to chemotherapy.