What happens when external org-wide defaults are set to public?

Setting external org-wide defaults to public means that all community users are granted access to view and edit records across the community without restrictions. This configuration allows community users to see all records of that object, which can lead to open access. Such an arrangement is beneficial in scenarios where information sharing is crucial, but it poses significant risks as it can lead to unintentional data leakage. Sensitive information may be exposed to users who should not have access to it, infringing on privacy and data security principles.

While the option mentioning full access for community users aligns closely with this openness, it does not sufficiently capture the possible severity of the consequences associated with public settings. The emphasis on the risk of data leakage highlights the importance of carefully considering org-wide defaults and their implications in a shared environment. Therefore, the correct answer conveys the essential caution required when managing access levels in external sharing scenarios.