This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fetal Skull and Maternal Pelvis, Subject name: Gynaecology & Obstetrics
[{'content': 'Which is the smallest transverse diameter of fetal head: \nSelect and explain. \nA. Biparietal, B. Bitemporal, C. Bimastoid, D. Super subparietal', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. (c) BimastoidRef: D.C. Dutta 8th ed. / 94-97TRANVERSE DIAMETERS OF FETAL HEAD* Biparietal: 9.5 cm* Bitemporal: 8 cm* Bimastoid: 7.5 cm; smallest transverse diameter* Super subparietal: 8.5 cm', 'role': 'assistant'}]