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 investigations is/are used for a diagnosis of hydatidiform mole? 
Select and explain. 
A. HCG titer, B. USG, C. Chest x ray, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: Hydatidiform mole can be diagnosed using HCG titer and transvaginal ultrasound. Chest Xray is usually done in these patients to rule out pulmonary metastasis of the trophoblast. Hydatidiform moles are characterised by high serum beta hCG levels more than 40,000mU/ml. Levels are higher with complete moles than with paial moles. Transvaginal ultrasound shows heterogeneous echogenic image and no fetus or placenta.