This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
[{'content': 'Implantation occurs at \nSelect and explain. \nA. 2-3 days, B. 6-7 days, C. 15-20 days, D. 20-25 days', 'role': 'user'}, {'content': 'Answer: B \nExplanation: HUMAN EMBRYOLOGY-INDERBIR SINGH TENTH EDITION-PAGE NO:72In humans implantation begins on the 6th day after feilization', 'role': 'assistant'}]