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
All the following are causative agents of sexually transmitted infections except 
Select and explain. 
A. Candida, B. Group B streptococcus, C. Echinococcus, D. Hepatitis B
C: Echinococcus
Answer: C: Echinococcus 
Explanation: Echinococcus is transmitted to humans by ingestion of eggs in dog’s faeces.