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: Unknown
[{'content': 'The obstetric conjugate diameter is the distance between the sacral promontory and the: \nSelect and explain. \nA. Nearest point on the posterior surface of the symphysis pubis, B. Upper part of the inner surface of the symphysis pubis, C. Apex of the pubic arch, D. Ilio-pectineal eminences', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Obstetric conjugate is the distance between the sacral promontory and the .nearest point on the posterior surface of the symphysis pubis.\n\xa0\nImportant points:\n\xa0 \xa0 \xa0 Obstetric conjugate measures 10 cm, It cannot be clinically measured but is to be inferred from diagonal conjugate or by lateral radiopelvimetry.\n\xa0 \xa0 \xa0 True/anatomical conjugate is the distance between midpoint of sacral promontory to the inner margin of CT. upper border of symphysis pubis. It measures 11 cm, Its measurement is inferred by subtracting 1.2 cm from ft diagonal conjugate.\n\xa0 \xa0 \xa0 \xa0Diagonal conjugate is the distance between the lower border of symphysis pubis to the midpoint on the s promontory. It is measures 12 cm. It is measured clinically during pelvic assessment.\n\xa0 \xa0 \xa0 \xa0Obstetric conjugate can be calculated by subtracting 1.5-cm from the diagonal conjugate.', 'role': 'assistant'}]