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
How many guinea worm cases were identified in the year 1999 - 
Select and explain. 
A. 0, B. 9, C. 2000, D. 4000
A: 0
Answer: A: 0 
Explanation: None