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': 'All are true regarding renal changes in normal pregnancy except \nSelect and explain. \nA. Serum creatinine decreases., B. GFR and Renal plasma flow increase by 50%., C. Increase in serum bicarbonate levels., D. Increased placental metabolism of AVP may cause transient diabetes insipidus during pregnancy.', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Serum bicarbonate levels decreased by 4\xa0→ 5m Eq / L due to decreased renal bicarbonate threshold.', 'role': 'assistant'}]