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
In instrumental vaginal delivery: 
Select and explain. 
A. 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
C: Forceps may be used if ventouse fails
Answer: C: Forceps may be used if ventouse fails 
Explanation: In case of failed ventouse, forceps may be used. Ref: Textbook of Obstetrics By Dutta, 4th Edition, Pages 397, 398, 613-614