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': 'A useful screening test for lead is measurement of which of the following? \nSelect and explain. \nA. Coproporphyrin in urine, B. Amino laevelunic acid in urine, C. Basophil in urine, D. Lead in morning urine sample', 'role': 'user'}, {'content': "Answer: A \nExplanation: Coproporphyrin in urine: Useful screening test. <150ug/L in non exposed persons. Amino laevulinic acid in urine: indicates lead absorption if > 5mg/L Lead level in urine: if >0.8 mg/L indicates lead exposure and absorption Basophillic stippling of RBC : sensitive parameter of hematological response Ref: Park's textbook of Preventive and Social Medicine, 21st Edition, Page-749", 'role': 'assistant'}]