This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General obstetrics, Subject name: Anatomy
[{'content': 'Factors which help in descent of presenting pa during labour are all except \nSelect and explain. \nA. Uterine contraction and retraction, B. Straightening of the fetal axis, C. Bearing down effos, D. Resistance from the pelvic floor', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Factors facilitating descent are Uterine contraction and retraction Bearing down effos Straightening of the fetal ovoid specially after rupture of membranes', 'role': 'assistant'}]