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': 'Anthrol acts as purgative due to - \nSelect and explain. \nA. Irritant action, B. Bulk formation in intestinal lumen, C. Osmotic action, D. Emollient effect', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Irritant action o Anthroquinones (senna, cascara sagrada) are stimulant purgatives --> irritate the intestinal mucosa and thus stimulate motor activity.", 'role': 'assistant'}]