Which best practice should the developer follow to control the unique and default content?

A developer created a landing page in CloudPages which return unique content when subscriber data is located on a related data extension. The developer does not know if all subscribers have rows in the related data extension, and want default content to render if no subscriber data is found on the related data extension.

Which best practice should the developer follow to control the unique and default content?
A . Use the RowCount function and an IF statement
B. Use the Lookup, Row and Field functions
C. Use the LookupOrderRows and Row functions
D. Use the DataExtensionRowCount function

Answer: A