Which feature allows you to protect sensitive information such as passwords when integrating Salesforce with external systems?

Named credentials are a feature within Salesforce that provides a secure way to store authentication information for external services. They eliminate the need to hard-code sensitive information, such as usernames and passwords, directly into Apex code or within connection settings. When integrating Salesforce with external systems, using named credentials allows for the seamless handling of authentication, as it caches the credentials securely and handles the passing of these credentials to the external service during API calls.

This approach minimizes the risk of exposing sensitive information by centralizing credential management and enabling secure communication between Salesforce and external systems. Named credentials also support various authentication mechanisms, including OAuth and basic authentication, making them versatile for different integration scenarios.

Other options, such as field-level security, sharing rules, and custom permissions, serve different purposes related to data visibility and access control but do not provide the same capability to manage sensitive authentication credentials securely during integrations.