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
[{'content': "O'Sullivan & Mahan criteria is used in :-- \nSelect and explain. \nA. Gestational hypertension, B. Gestational diabetes mellitus, C. Rh incompatibility, D. Assessing progress of labour", 'role': 'user'}, {'content': "Answer: B \nExplanation: Diagnosis of Gestational Diabetes Mellitus (GDM ) is made following a 100 gm glucose load based on criteria laid down by O'Sullivan and Mahan.", 'role': 'assistant'}]