What is the purpose of the KEEP statement?

The KEEP statement is utilized in SAS to specifically control which variables are retained in the output dataset. When you implement the KEEP statement, you list the variables you want to keep, and all others will be excluded from the resulting dataset. This is particularly useful when working with large datasets where you might only need a subset of variables for further analysis or reporting. By using the KEEP statement, you can simplify your dataset and improve processing efficiency by focusing only on the relevant data.

Other options address different functionalities within SAS: removing duplicates requires distinct procedures, renaming variables involves the RENAME statement, and sorting the order of variables is managed through the ORDER statement or by defining the variables in the desired sequence directly in the DATA step. Each of these serves its own purpose but does not achieve the specific objective of retaining specified variables in the output, which is the primary role of the KEEP statement.