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: Gynaecology & Obstetrics
[{'content': 'In instrumental vaginal delivery: \nSelect and explain. \nA. Full cervical dilatation is the only pre-requisite, B. Forceps are used in all cases of breech delivery, C. Forceps may be used if ventouse fails, D. Ventouse can not be used in rotational occipito-transverse/posterior delivery', 'role': 'user'}, {'content': 'Answer: C \nExplanation: In case of failed ventouse, forceps may be used. Ref: Textbook of Obstetrics By Dutta, 4th Edition, Pages 397, 398, 613-614', 'role': 'assistant'}]