This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
[{'content': 'Major pa of cardiac septa development is completed by day: \nSelect and explain. \nA. 25, B. 27, C. 35, D. 37', 'role': 'user'}, {'content': "Answer: D \nExplanation: The major septa of the hea are formed between the 27th and 37th days of development, when the embryo grows in length from 5 mm to approximately 16 to 17 mm. Ref: Langman's embryology 11th edition Chapter 12.", 'role': 'assistant'}]