This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Communicable diseases, Subject name: Social & Preventive Medicine
[{'content': 'Patient was given chloroquine & doxycycline for 7 days. Patient&;s fever decreases in 4 days but , peripheral smear showed occasional gametocytes of plasmodium falciparum. This type of drug resistance is - \nSelect and explain. \nA. R1 type, B. R2 type, C. R3 type, D. R4 type', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Types of Drug Resistance In defining criteria for resistance to the aminoquinolineantimalarial drugs, the WHO has described three grades of resistance following treatment (Low grade) R1 : Recrudescence of infection between 7 and 28 days of completing treatment following initial resolution of symptoms and parasite clearance. (High grade) R2 : Reduction of parasitaemia by > 75% at 48 hours but failure to clear parasites<br />within 7 days. R3 : Parasitaemia does not fall by >75% within 48 hours. (www.slideshare.net)', 'role': 'assistant'}]