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
[{'content': 'Zona hatching occurs: \nSelect and explain. \nA. 4 days after feilisation, B. 5 days after feilisation, C. 6 days after feilisation, D. 8 days after feilisation', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Zona hatching occurs just before the implantation i.e,5 days after feilisation. Ref: Datta textbook of Obstetrics - 9e pg24.', 'role': 'assistant'}]