What dialog must the user display to create a tag in the PLC programming environment?

To create a tag in the PLC programming environment, the user must display the "New tag dialog." This specific dialog is designed to facilitate the creation of new tags by providing the necessary fields for defining the tag's name, data type, initial value, and other relevant properties. By using this dialog, users can ensure that they are properly configuring the tag in accordance with the requirements of the programmable logic controller (PLC).

In contrast, the other options do not directly pertain to the creation of tags; they serve different purposes within the PLC programming environment. The "Tag settings" option may be used to modify existing tags, while the "Project manager" is typically for navigating through the project's architecture and components rather than for creating new entries. The "Help menu" is a resource for obtaining support or information about the software and its features but does not offer functionality for creating tags.

Thus, the "New tag dialog" is the essential tool specifically meant for this action.