This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Gynaecology & Obstetrics
Ideally, traction during vacuum extraction should be applied in which of the following manner? 
Select and explain. 
A. Continously, B. Intermittently with cycles of 20seconds of traction followed by 1minute of rest, C. Intermittently and with contractions, D. Intermittently and between contraction
C: Intermittently and with contractions
Answer: C: Intermittently and with contractions 
Explanation: After the vacuum is applied, Effo should be intermittent and coordinated with maternal expulsive effos and contractions(Ref: William's Obstetrics; 25th edition)