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': 'Mechanism of action of tianeptin in the brain is: \nSelect and explain. \nA. Selective serotonin reuptake inhibition, B. Selective serotonin reuptake enhancement, C. Selective dopamine reuptake inhibition, D. Selective norepinephrine reuptake inhibition', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]