This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Abnormal labor, Subject name: Gynaecology & Obstetrics
[{'content': 'Engaging diameter in brow presentation is \nSelect and explain. \nA. Mento-veical, B. Mento-bregmatic, C. Suboccipito-bregmatic, D. Occipito-frontal', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Brow presentation : Engaging diameter of head is Mentoveical which is 14 cm The position is commonly unstable and conves to either veex or face presentation Position can be confirmed by Palpating supraorbital ridges and anterior fontanel. Ref: Dutta Obs 9e pg 367.', 'role': 'assistant'}]