This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology, Subject name: Microbiology
[{'content': 'Oakley-Fulthorpe procedure is: \nSelect and explain. \nA. Single diffusion in one dimension, B. Double diffusion in one dimension, C. Single diffusion in two dimensions, D. Double diffusion in two dimensions', 'role': 'user'}, {'content': 'Answer: B \nExplanation: *Various immunodiffusion test *Single diffusion in one dimension - Oudin procedure *Double diffusion in one dimension - Oakley fulthorpe procedure *Single diffusion in two dimensions - Radial immunodiffusion *Double diffusion in two dimensions - Ouchterlony procedure', 'role': 'assistant'}]