Which option shows only the main master timecode in Premiere?

The option that shows only the main master timecode in Premiere is the Master option. The master timecode represents the total length of the sequence and reflects the overall progression of time across the entire timeline in the editing environment. This timecode is crucial for editors as it helps them understand where they are in the sequence and allows them to maintain synchronization with audio, video clips, and other elements being managed.

It provides a straightforward reference point for the entire project rather than focusing on specific aspects like remaining time or the duration of clips, which may be shown in other contexts. Understanding the master timecode is vital for effective editing and ensures that all elements align correctly throughout the final output. This is why the Master option is specifically designed to present this information clearly to the user.