This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Normal Labour, Subject name: Gynaecology & Obstetrics
[{'content': 'Arrest disorder is defined as the cessation of cervical dilatation in active phase of labor of more than: \nSelect and explain. \nA. 1 hour, B. 1.2 hours, C. 1.5 hours, D. 2 hours', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. D. 2 hours* Secondary arrest is defined when the active phase of labor (cervical dilatation) commences normally but stops or slows significantly for 2 hours or more prior to the full dilatation of the cervix.* It is commonly due to malposition or cephalopelvic disproportion.'Cessation of active phase of dilatation by more than 2 hours is defined as arrest' Danforth.", 'role': 'assistant'}]