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
A lady has ovarian mass, x-ray pelvis shows a radio-opaque shadow. The probable diagnosis is: 
Select and explain. 
A. Mucinous cyst adenoma, B. Serous cyst adenoma, C. Dysgerminoma, D. Dermoid cyst
D: Dermoid cyst
Answer: D: Dermoid cyst 
Explanation: None