What occurs when you enter a URL that requests an API?

When you enter a URL that requests an API, the standard behavior involves an initial authentication step before any data is returned. This process ensures that only authorized users can access the information provided by the API. Once authentication is successfully completed, such as through API keys, OAuth tokens, or other methods, the API can then return the requested data.

This process is important for maintaining security and protecting sensitive data. Many APIs require some form of authentication to verify the identity of the requester and to ensure that they have the necessary permissions to access the data being requested. Therefore, option C accurately reflects the standard operations that occur when an API request is made.

The alternative scenarios involve either immediate data return without proper checks or generating errors, which do not align with the typical functioning of a secured API.