<prompt> 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 -R1 typeR2 typeR3 typeR4 type  <response>: 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 parasiteswithin 7 days. R3 : Parasitaemia does not fall by 75 within 48 hours. 