Final answer:
To display the current date in a report, an unbound text box control should be added with the syntax '=Date()' to automatically show the system's current date.
Step-by-step explanation:
To display the current date in a report you can add an unbound text box control and enter the current date as a function. The correct syntax to use in a reporting tool like Microsoft Access is =Date(). This function will automatically display the current system date in the report. Other options listed, such as current_date(), current_date, and currentdate(), are not correct in the context of most reporting and database software.