Which option can be used to remove duplicate observations from a dataset?

The option to employ the NODUPKEY option in PROC SORT is effective for removing duplicate observations from a dataset. When you use PROC SORT with the NODUPKEY option, SAS sorts the data and then eliminates any duplicate records based on the values of the specified key variables. Only the first occurrence of each unique key value is retained, making this method particularly efficient for ensuring data uniqueness when working with large datasets.

Using a WHERE clause in a DATA step does not inherently remove duplicates; it is typically used for subsetting data based on specific conditions. The presence of duplicates could still remain in the resulting dataset after the WHERE filtering is applied.

The DELETE statement within PROC SQL might also be thought of as a candidate for removing duplicates, but it needs a specific condition to target duplicates, which could make it more complex and less straightforward than using the NODUPKEY option in PROC SORT.

Applying the DISTINCT keyword in PROC MEANS is aimed at calculating summary statistics without duplicates, but it does not modify the dataset itself. Instead, it affects the output of summary statistics generated from the dataset without changing the actual records.

Thus, the use of the NODUPKEY option in PROC SORT stands out as a direct and efficient method for achieving the goal of