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: Pediatrics
[{'content': "Which of the following is a sonographic finding of a fetus with Down's syndrome? \nSelect and explain. \nA. 'Sandal gap', B. Mild renal pelvis dilation, C. Nasal bone absence, D. All of the above", 'role': 'user'}, {'content': 'Answer: D \nExplanation: Second-trimester sonographic markers or "soft signs" associated with Down syndrome fetuses: Nuchal fold thickening Nasal bone absence or hypoplasia Shoened frontal lobe or brachycephaly Sho ear length Echogenic intracardiac focus Echogenic bowel Mild renal pelvis dilation Widened iliac angle Widened gap between first and second toes--"sandal gap" Clinodactyly, hypoplastic mid-phalanx of fifth digit Sho femur Sho humerus Ref: Cunningham F.G., Leveno K.J., Bloom S.L., Hauth J.C., Rouse D.J., Spong C.Y. (2010). Chapter 13. Prenatal Diagnosis and Fetal Therapy. In F.G. Cunningham, K.J. Leveno, S.L. Bloom, J.C. Hauth, D.J. Rouse, C.Y. Spong (Eds), Williams Obstetrics, 23e', 'role': 'assistant'}]