This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Gynaecology & Obstetrics
[{'content': 'Risk for postnatal urinary abnormality is severe if Renal pelvic dilatation is ----- in third trimester? \nSelect and explain. \nA. 4 to < 7mm, B. 7 to < 9mm, C. 9 to <= 15mm, D. > 15mm', 'role': 'user'}, {'content': "Answer: D \nExplanation: Risk for Postnatal Urinary Abnormality According to Degree of Renal Pelvis DilatationDilatationSecond trimesterThird trimesterPostnatal abnormalityMild4 to < 7mm7 to < 9mm12%Moderate7 to <= 10mm9 to <= 15mm45%Severe> 10mm> 15mm88%(Ref: William's Obstetrics; 25th edition)", 'role': 'assistant'}]