This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General obstetrics, Subject name: Gynaecology & Obstetrics
[{'content': 'Snowstorm appearance in sonography is characteristic of \nSelect and explain. \nA. Complete molar pregnancy, B. Ectopic pregnancy, C. Incomplete aboion, D. Missed aboion', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Sonographically, a complete mole appears as an echogenic uterine mass with numerous anechoic cystic spaces but without a fetus or amniotic sac. The appearance is often described as a "snowstorm"Paial mole has features that include a thickened, multicystic placenta along with a fetus or at least fetal tissueReference: William\'s Obstetrics; 25th edition, chapter 20; Gestational trophoblastic diseases', 'role': 'assistant'}]