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: Pathology
Patau syndrome due to - 
Select and explain. 
A. Trisomy 21, B. Trisomy 13, C. 18 P, D. Trisomy 18
B: Trisomy 13
Answer: B: Trisomy 13 
Explanation: None