This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Preterm Labour & Interauterine Fetal Death, Subject name: Gynaecology & Obstetrics
[{'content': 'Cut off value of cervical length for prediction of preterm labor? \nSelect and explain. \nA. 1.5 cm, B. 2.5 cm, C. 3.5 cm, D. 4.5 cm', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans- B. To diagnose preterm Labour cervical length must be less than 2.5 cm .', 'role': 'assistant'}]