Final answer:
The correct place to start specifying data requirements in a new software system is with the input and output flows on the use case diagram.
Step-by-step explanation:
The correct place to start specifying data requirements in a new software system is with the input and output flows on the use case diagram. A use case diagram provides a visual representation of the interactions between actors (users or external systems) and the system. By analyzing the input and output flows on the use case diagram, you can identify the necessary data requirements for the system.