input: The following are multiple choice questions (with answers) about medical knowledge.   **Question:** Like all opioids, tramadol acts as an analgesic drug by stimulating mu opioid receptors. Apa from this, the additional mechanism of action of tramadol is?   (A) Serotonin and nor-adrenaline reuptake inhibition   (B) Anticholinergic   (C) Antihistaminic   (D) Serotonin and dopamine reuptake inhibition
output: ['(A) Serotonin and nor-adrenaline reuptake inhibition <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Serotonin and nor-adrenaline reuptake inhibition  (B) Anticholinergic  (C) Antihistaminic  (D) Serotonin and dopamine reuptake inhibition <> possible answers', '  Like all opioids, tramadol acts as an analgesic drug by stimulating mu opioid receptors. Apa from this, the additional mechanism of action of tramadol is? <> context']