When the following SAS program runs, how many PDF files are created? ODS PDF FILE='results.pdf'; PROC PRINT DATA=work.ds1; RUN; PROC FREQ DATA=work.ds1; PROC FREQ DATA=work.ds2; RUN; ODS PDF CLOSE;

The program in question opens a PDF output destination with the statement ODS PDF FILE='results.pdf';. This initializes the output for all subsequent procedures that produce output until the PDF destination is closed with ODS PDF CLOSE;.

Throughout the program, two procedures are executed: PROC PRINT and PROC FREQ. Both of these procedures generate output that will be captured in the file 'results.pdf' because they are called after the ODS PDF FILE statement has been executed and before the PDF is closed. Since there is no ODS PDF FILE statement that opens a new PDF file in between the procedures, all the output produced from both PROC PRINT and PROC FREQ commands will be consolidated into one single PDF document.

Therefore, the total number of PDF files created is just one, which contains all output from both procedures combined. This approach is beneficial for managing output by keeping it organized in a single file.