Final answer:
The Application Setup menu is the correct tool to use for creating a data model in a Salesforce environment, while other options like the Force.com Data Loader, Force.com IDE, and Webservices API serve different purposes.
Step-by-step explanation:
Which Developer Tool Can Be Used to Create a Data Model?
The developer tool that can be used to create a data model in a Salesforce environment is the Application Setup menu. The Force.com Data Loader is primarily used for the bulk import or export of data. The Force.com IDE is an integrated development environment, useful for coding but not specifically for creating data models. The Webservices API allows for programmatic access to your org's information, but it is not used to create data models directly. It is the Application Setup menu that contains the tools you need to build and modify the data model, such as creating objects, fields, and relationships between objects.