Final answer:
A specific disease and a specific operation would be included in a registry, while case finding and case file would be part of an index.
Step-by-step explanation:
Elements included in a registry, rather than an index, are those that are specific and individualized. In this case, a specific disease (option A) and a specific operation (option B) would be included in a registry since they refer to individual cases. On the other hand, case finding (option C) and case file (option D) would be more likely to be part of an index, which is a comprehensive list or database of cases.