How do you create an index on a SAS dataset?

Creating an index on a SAS dataset is an essential task to improve the speed of data retrieval operations. The correct method for accomplishing this is to use the INDEX statement in a DATA step or the CREATE INDEX option in PROC SORT.

Using the INDEX statement within a DATA step allows a programmer to define an index as the data is being created or modified. This means that when new records are added or existing ones are updated, SAS maintains the index automatically, allowing for faster lookups based on the indexed variables.

Additionally, the CREATE INDEX option in PROC SORT directly creates an index on the sorted dataset. This method is particularly useful when you want to quickly sort and index a dataset in one step, which can greatly enhance performance during subsequent queries and operations on the indexed variables.

In summary, option B correctly identifies the two official methods provided by SAS for creating an index, ensuring that you achieve efficient data access and management in your datasets.