This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General obstetrics, Subject name: Anatomy
CPD in absence of gross pelvic abnormality can be diagnosed by 
Select and explain. 
A. Ht of mother < 158 cms, B. Trial of labor, C. X ray pelvimetry, D. Pelvic examination
B: Trial of labor
Answer: B: Trial of labor 
Explanation: Best method to rule out CPD is trial of labor Best investigation MRI