What does the DROP statement do in a DATA step?

The DROP statement in a DATA step is specifically designed to remove specified variables from the dataset being created or modified. When you include the DROP statement and list the variables you want to exclude, those variables will not appear in the output dataset. This is particularly useful when you want to streamline your dataset by eliminating unneeded variables that may not be relevant to the analysis or reporting, thereby simplifying subsequent data handling.

The other choices involve actions that the DROP statement does not perform. The first option refers to changing variable names, which is done using the RENAME statement, not the DROP statement. The third option about filtering observations pertains to the WHERE statement or subsetting techniques, not variable removal. The last option mentions the creation of new variables, which is achieved through assignment statements within the DATA step. Thus, the clarity and purpose of the DROP statement is in its ability to remove specific variables from the dataset.