This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other topics and Adverse effects, Subject name: Anatomy
If a drug is active against pre erythrocytic stage of the malaria parasite it will be useful as 
Select and explain. 
A. Suppressive prophylactic, B. Causal prophylactic, C. Clinical curative, D. Radical curative
B: Causal prophylactic
Answer: B: Causal prophylactic 
Explanation: (Ref KDT 6/e p782) Stage ---clinical use Preerythrocytic- Causal prophylaxis Erythrocytic-Clinical cure -Suppressive prophylaxis Exo-Erythrocytic: Radical cure Gametocytic Pevention of transmission