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: Social & Preventive Medicine
[{'content': 'L-J chart is used for monitoring -a)  Accuracyb)  Precisionc)  Sensitivityd)  Specificity \nSelect and explain. \nA. ac, B. ab, C. ad, D. bc', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The formulation of Westgard rules were based on statistical methods. \nWestgard rules are commonly\xa0used\xa0to analyse data in Shewhart control\xa0Charts\xa0Westgard rules are\xa0used\xa0to define specific performance limits for a particular assay and can beused\xa0to detect both random and systematic errors.', 'role': 'assistant'}]