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: Anatomy
[{'content': 'Double bleb sign in USg are depictive of: \nSelect and explain. \nA. Intrauterine two gestations sac, B. Amniotic sac and yolk sac, C. Ectopic pregnancy, D. Heterotopic pregnancy', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Double bleb sign : Visualization of gestational sac containing a yolk sac and amniotic sac giving an appearance of two small bubbles . Feature of an intrauterine pregnancy. Distinguishes a pregnancy from a pseudogestational sac or decidual cast cyst. Ref:Williams 24e pg 170.', 'role': 'assistant'}]