This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Medical, surgical and gynaecological illness complicating pregnancy, Subject name: Gynaecology & Obstetrics
[{'content': 'According to NYHA grading, Patients with marked limitation to physical activity belongs to \nSelect and explain. \nA. Grade I, B. Grade II, C. Grade III, D. Grade IV', 'role': 'user'}, {'content': 'Answer: C \nExplanation: New York Hea Association Functional Classification of Cardiac diseaseGrade I: Patients have no limitation of physical activityGrade II: Patients have slight limitation of physical activityGrade III: Patients have marked limitation of physical activityGrade IV: Patients have an inability to carry on the physical activity without symptomsReference: Practical Guide to High-Risk Pregnancy and Delivery; Chapter 20; Cardiac Disease and Pregnancy', 'role': 'assistant'}]