A. R1 type.
B. R2 type.
C. R3 type.
D. R4 type.
WHO classification of antimalarial drug resistance
1. S-sensitive → If a sexual parasites have cleared by day 6 from the begining of treatment wihout subsequent recrudescence until day 28.
2. R1-Low grade resistance → Recrudescence of infection between 7-28 days of completing treatment.
3. R2-High grade resistance → Reduction of parasitemia by more than 75% at 48 hours of completing treatment but failure to clear the organism within 7 days.
4. R3→ Parasitemia does not fall by more than 75% within 48 hours of compleing treatment and there is no subsequent clearance of asexual parasites.