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: Social & Preventive Medicine
[{'content': 'All the following are causative agents of sexually transmitted infections except \nSelect and explain. \nA. Candida, B. Group B streptococcus, C. Echinococcus, D. Hepatitis B', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Echinococcus is transmitted to humans by ingestion of eggs in dog’s faeces.', 'role': 'assistant'}]