This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Development period- week 1,2,3,4, Subject name: Anatomy
[{'content': 'During week 2 of development, the embryoblast receives its nutrients \nSelect and explain. \nA. Diffusion, B. Osmosis, C. Reverse osmosis, D. Fetal capillaries', 'role': 'user'}, {'content': 'Answer: A \nExplanation: During week 2 of development, the embryoblast receives its nutrients from endometrial blood vessels, endometrial glands, and decidual cells diffusion. Diffusion of nutrients does not pose a problem, given the small size of the blastocyst during week 2. Although the beginnings of a uteroplacental circulation are established by end of week 2, no blood vessels have yet formed in the extraembryonic mesoderm to carry nutrients directly to the embryoblast (this occurs in week 3 - day17).', 'role': 'assistant'}]