What is the advantage of a case study, and what is its disadvantage?

Its advantage is that it produces a great deal of information about the person$($s$)$ being studied. Its disadvantage is that its results may not generalize to most other people.

Its advantage is that it's inexpensive to conduct. Its disadvantage is that it doesn't reveal a lot of information.

Its advantage is that it can be conducted very quickly. Its disadvantage is that it's very expensive to conduct.

None of these responses are correct.