This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Screening, Subject name: Social & Preventive Medicine
[{'content': 'Reliability means \nSelect and explain. \nA. Number of times the same results on repeated trials, B. Number of times variation is seen, C. Extent of accuracy, D. Level of simplicity', 'role': 'user'}, {'content': 'Answer: A \nExplanation: ref: Park&;s 23rd edition pg138 Reliability / repeatability / precision: that is test must give consistent results when repeated more than once on the same individual or material, under the same conditions. note: Validity or accuracy: given by sensitivity and specificity. Diagnostic power or Predictablity: includes positive and negative predictive values. in order to include or exclude the person.', 'role': 'assistant'}]