Which feature helps ensure that only trusted apps can be installed on macOS?

Gatekeeper is a security feature in macOS designed to help ensure that only trusted apps are installed and executed on the system. It accomplishes this by allowing users to set preferences for where applications can be downloaded from. By default, Gatekeeper restricts app installations to those from the Mac App Store and identified developers, which helps protect users from malware and other potentially harmful software.

This feature prompts users when they attempt to open an app that was downloaded from an unapproved source, providing an additional layer of verification before the app can run. Users can override Gatekeeper's restrictions if they choose, but this initial barrier significantly enhances the overall security of the macOS environment by minimizing the risk of running unverified applications.

Other features listed, such as App Sandbox, Secure Boot, and Permissions Manager, serve different purposes in terms of security. The App Sandbox isolates apps to limit their access to system resources, Secure Boot ensures that only a legitimate version of macOS is loaded at startup, and Permissions Manager handles the access rights of apps to user data and system resources. While all contribute to system security, Gatekeeper is specifically focused on controlling the installation and execution of applications based on their sources.