Which option correctly uses an ANSI standard column modifier for a column label?

The correct answer is based on how ANSI standard column modifiers are utilized in SAS. In ANSI SQL, column labels can be defined directly using the AS keyword or by using specific syntax that aligns with SQL standards.

The option labeled 'Employee Number' is clear in its intent to represent a column label but lacks the required context to be recognized correctly as a column modifier. It does not provide any syntax specific to column labeling or the required formal declaration that ANSI standards usually demand.

In contrast, the use of the equal sign in the first option (Label= 'Employee ID') indicates a SAS-specific syntax rather than ANSI SQL. While it does identify the column label properly, it is more aligned with SAS code rather than ANSI standards.

The third option, 'Header=Employee Reference Number', employs the term "Header," which is not the proper column modifier accepted in ANSI SQL conventions.

Hence, the option that accurately reflects the use of a standard format visible in ANSI SQL practices is the direct reference to the column title without the need for additional signage or declarations, which aligns well with ANSI standards for simplicity and clarity.