This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fetal Skull and Maternal Pelvis, Subject name: Gynaecology & Obstetrics
Longest fetal diameter: 
Select and explain. 
A. Biparietal, B. Suboccip tobregmatic, C. Occipitofrontal, D. Mentovertical
D: Mentovertical
Answer: D: Mentovertical 
Explanation: Ans is d, i.e. MentoverticalFetal diameters-AP diameters are always longer than Transverse diameter of fetal head.Longest diameter is-Mentovertical diameter (14 cms) followed by submentovertical diameter.