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
Which one of the following drug may be used for prevention of relapse of P. vivax infection - 
Select and explain. 
A. Chloroquine, B. Primaquine, C. Atovaquone, D. Tetracycline
B: Primaquine
Answer: B: Primaquine 
Explanation: Ans. is 'b' i.e., Primaquine