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': 'Net weight gain in pregnancy is : \nSelect and explain. \nA. 11 lb, B. 24 lb, C. 36 lb, D. 42 lb', 'role': 'user'}, {'content': 'Answer: B \nExplanation: 24 lb', 'role': 'assistant'}]