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
Engagement of foetal head is with reference to : 
Select and explain. 
A. Biparietal diameter, B. Bitemporal diameter, C. Occipito frontal diameter, D. Suboccipito frontal diameter
A: Biparietal diameter
Answer: A: Biparietal diameter 
Explanation: Biparietal diameter