Which application's URL format should external users use to access the community via mobile?

The choice of using the URL format that includes "one/one.app" is correct because this format is specifically designed for mobile access to Salesforce communities. This URL directs users to the Salesforce mobile app interface, which optimizes the community experience for users on mobile devices. When external users utilize this format, they benefit from a responsive design and a layout that is tailored for smaller screens, ensuring that navigation remains user-friendly and efficient.

Mobile users require a streamlined experience to access community resources and engage with content effectively. The one.app designation indicates that this URL takes advantage of the Salesforce mobile application framework, which enhances performance and accessibility.

Other URL formats mentioned may not provide the same optimized mobile experience, as they are designed for general web access or other purposes, making them less suitable for mobile use. Therefore, the URL containing "one/one.app" is the ideal choice for external users looking to access the community via mobile devices.