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: Pharmacology
[{'content': 'If a drug is active against the pre–erythrocytic stage of the malarial parasite it will be useful as a : \nSelect and explain. \nA. Suppressive prophylactic, B. Causal prophylactic, C. Clinical curative, D. Radical curative', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]