What is the purpose of a DO-END block in SAS?

The purpose of a DO-END block in SAS is to execute statements as a unit, usually within an IF-THEN/ELSE structure. This allows multiple statements to be grouped together and run conditionally based on the evaluation of a logical expression. By using a DO-END block, you can specify a set of actions that should occur only when a particular condition is met, ensuring that all statements within the block are executed in sequence and treated as a single logical operation.

This structure is particularly useful when you want to perform multiple operations based on a single condition without needing to repeat the conditional logic for each operation. It enhances code readability and maintainability by keeping related statements bundled together.

In other contexts, while options such as executing statements repetitively or looping through each observation might utilize DO loops, they are not the primary purpose of the DO-END block. Similarly, variables can be defined in a DATA step, but this is not the specific function of a DO block. Hence, the option focusing on executing statements as a unit accurately captures the intent and functionality of the DO-END structure in SAS programming.