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': 'What is the action of oxytocin in small doses, when used as intravenous infusion in a full term uterus ? \nSelect and explain. \nA. Relaxes uterus, B. Induces uterine contractions, C. Causes cervical dilatation, D. All', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]