We can confirm that a case study matches the description put forward by option C in the question statements in that it is used to study a single individual or group.
<h3 /><h3>What exactly is a case study?</h3>
In research, a case study is when a single individual or group is studied in great depth, as described by option C. Case studies are more often done in groups in order to better compare results between various groups and can be very useful in providing a deeper insight into behavior or patterns.
Therefore, we can confirm that a case study is when a single individual or group is studied in great depth. Option C is correct.
