This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Epidemiology, Subject name: Social & Preventive Medicine
'Ring vaccination' is 
Select and explain. 
A. Given by a ring shaped machine, B. Given to produce a ring lesion, C. Given around 100 yards of a case detected, D. Given around a mile of a case
C: Given around 100 yards of a case detected
Answer: C: Given around 100 yards of a case detected 
Explanation: Ring vaccination is a strategy to inhibit the spread of disease by vaccinating only those who are most likely to be infected.