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: Dental
Which of the following is a step in case-control study? 
Select and explain. 
A. Selection, B. Matching, C. Analysis, D. All of the above
B: Matching
Answer: B: Matching 
Explanation: There are four basic steps in conducting a case control study:

Selection of cases and controls
Matching
Measurement of exposure, and
Analysis and interpretation

Reference: Essentials of Preventive and Community Dentisitry, Soben Peter , 4th ed page no 59