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: Gynaecology & Obstetrics
Which of the following ovarian tumour is most prone to undergo torsion during pregnancy? 
Select and explain. 
A. Serous cystadenoma, B. Mucinous cystadenoma, C. Dermoid cyst, D. Theca lutein cyst
C: Dermoid cyst
Answer: C: Dermoid cyst 
Explanation: “Incidence of dermoid cyst increases two times in pregnancy and it becomes the most commonly diagnosed ovarian tumour during pregnancy.”
Dutta Obs. 7/e, p 310
“A benign cystic teratoma is the most common neoplasm to undergo torsion.”
Novak 14/e, p 510