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': 'Gestational diabetes is diagnosed by : \nSelect and explain. \nA. Glucose tolerance test, B. Random blood sugar, C. Fasting and postprandial blood sugar, D. 24 hours blood glucose profile', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Glucose tolerance test', 'role': 'assistant'}]