The correct answer is D. This option uses the PROC PRINT procedure, which is used to print SAS data sets. The format statement within PROC PRINT temporarily assigns a format to a variable for the duration of the PROC PRINT step. Here is how it works:

data=sashelp.shoes; tells SAS which dataset to print.

Format sales comma12.; temporarily assigns a comma format to the sales variable, making it easier to read, especially if the numbers are large. The comma12. format adds commas for thousands, millions, etc., and displays the number in a field that is 12 characters wide.

The format is only applied for the duration of the PROC PRINT step and does not permanently change the dataset.

The other options are incorrect for the following reasons:

Option A attempts to use a PROC FORMAT step, which is for creating custom formats, not for assigning formats to variables in a dataset.

Option B uses a DATA step which could permanently assign the format to the sales variable if it were syntactically correct (it should be set sashelp.shoes; instead of Set sashelp,sheoes;).

Option C mentions PROC CONTENTS which displays metadata about variables in a dataset and does not have the capability to assign formats.

References:

SAS 9.4 documentation for the PROC PRINT statement: SAS Help Center: PROC PRINT