This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Concepts of Immunity, Classification of Vaccines, Subject name: Social & Preventive Medicine
[{'content': 'BCG vaccine is diluted with: \nSelect and explain. \nA. Normal saline, B. Distilled water, C. Dextrose, D. Colloids', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Lyophilized vaccines & their diluents: BCG vaccine - Normal saline Yellow fever vaccine - cold saline Japanese Encephalitis - phosphate buffer saline HiB - DPT / saline Measles, MMR - Distilled /sterile water', 'role': 'assistant'}]