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': 'When a diagnostic test is used in series mode then- \nSelect and explain. \nA. Sensitivity increases but the specificity decreases, B. Specificity increases bu the sensitivity decreases, C. Both sensitivity and specificity increases, D. Both sensitivity and specificity decreases', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ref:Parks 23rd edition pg 137 When used in series: Sensitivity decreases Specificity increases PPV increases NPV decreases When used in parallel : Sensitivity increases Specificity decreases PPV decreases NPV increases', 'role': 'assistant'}]