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: Skin
[{'content': 'The rash in measles occurs first in occurs first in the .....region : \nSelect and explain. \nA. Forehead, B. Post auricular, C. Chest, D. Neck', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. Post auricular', 'role': 'assistant'}]