This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Biostatistics, Subject name: Social & Preventive Medicine
[{'content': 'Measure of dispersion is:(1994) \nSelect and explain. \nA. Mean, B. Mode, C. Standard deviation, D. Median', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans: cRef: Park, 17th ed, p. 612 & 18,h ed, p. 646', 'role': 'assistant'}]