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
In which year did the Kyoto Protocol come into force? 
Select and explain. 
A. 2001, B. 2003, C. 2005, D. 2007
C: 2005
Answer: C: 2005 
Explanation: None