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': 'All are true about levamisole EXCEPT : \nSelect and explain. \nA. Act as an immunostimulator, B. Act as an immunodepressor in high doses, C. Single dose is sufficient for the treatment of psoriasis, D. Acts as antihelminthic by causing depolarization', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Levamisole is an immunomodulator acting as immunostimulant at low doses and immunodepressant at high doses.\nIt was used as anti-helminthic and causes depolarization by stimulating nicotinic receptors.\nIt is used for the treatment of colorectal carcinoma in combination with 5-FU.\nIt is slow to act in psoriasis and requires two-day therapy per week for prolonged periods.', 'role': 'assistant'}]