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
Chandler's index is associated with which of the following infestation? 
Select and explain. 
A. Hook worm, B. Round worm, C. Pin worm, D. Whip worm
A: Hook worm
Answer: A: Hook worm 
Explanation: Chandler's index is used in the epidemiological studies of hook worm. It refers to the average number of hook worm eggs per gram of feaces. Chandler's index less than 200 is not significant, value between 200 - 250 indicates potential danger, value between 250 - 300 indicates a minor health problem and value greater than 300 indicates a major health problem.