What action should be taken to exit out of the diagram check and return to normal mode?

To exit out of the diagram check and return to normal mode, clicking the X is the appropriate action. This action is typically designed to close pop-up windows or modal dialogs in software applications, which often include diagram checks or validation checks. Upon clicking the X, users can seamlessly transition back to the primary working mode without saving any changes or being prompted for additional input.

Other options, such as clicking the home button, may redirect the user back to the main dashboard rather than simply exiting the current mode, which could disrupt their workflow. Clicking cancel often serves to dismiss changes or closes prompts but does not explicitly indicate returning to normal mode. Lastly, clicking exit could imply a full exit from the application rather than just closing the check interface. Thus, clicking the X effectively fulfills the requirement to return to normal mode efficiently and is aligned with standard user interface practices.