Option D is the correct snippet It uses 'KEEP=' within the 'SET' statement to select only the 'ORDER_ID' and 'PRODUCT_ID' variables for output. The 'IF' statement filters the data to include only orders from January 2023. The 'TOTAL _ VALUE' variable is calculated within the DATA step- Option A is incorrect because it includes 'SALES_DATE' which is not needed in the final output_ Option B is incorrect because 'KEEP:' is used outside the 'SET' statement, which is not valid syntax. Option C is incorrect because it drops 'QUANTITY', 'PRICE', and 'DISCOUNT while still using them in the calculation. Option E is incorrect because it attempts to 'KEEP' the 'TOTAL _ VALUE' variable but the variable is not yet created at that point in the code.

Option C correctly combines the data sets vertically using the SET statement and then dynamically reorders the variables using an array and the call symput function to ensure the specific variable order Options A and E simply combine the data sets without specifying order, and Option B and D drop variables, which is not desired. Option C utilizes the _ N _ system variable, which is essential for dynamic variable ordering.

The 'put()' function is used to format the output of a variable. In this case, we are using the 'Smonname.' format to display the full month name. Option A is incorrect because it uses the 'monname. format without the dollar sign, which is not the correct format for displaying the full month name. Option C and D are incorrect because they use the 'wordname.' format, which is used to display the weekday name. Option E is incorrect because it uses the 'date9.' format, which displays the date in the format 'YYYY-MM-DD'.

The message "NOTE: The data set WORK.TEMP_DATA has 0 observations and 10 variables." Indicates that the data set WORK. TEMP DATA has been successfully created, but it contains no data (0 observations). The 10 variables are defined, but there are no rows of data populated.

The correct answer is A- The 'OTHER keyword in PROC FORMAT allows you to define a label for any value that doesn't explicitly match a previous range or value in the format. In this case, 'LOW - HIGH = 'Age Provided" covers all non-missing values, while 'OTHER covers any missing values. Option B uses a period (e), which represents a missing value, but this approach is less flexible for different missing value types. Option C uses the 'MISSING' keyword, which is specific to missing values and might not handle all possible missing value representations. Options D and E are incorrect because they explicitly label only a specific string (blank space or 'Unknown Age').