Which two applications allow on-demand screen sharing even when the screen sharing service is disabled?

The answer is correct because both Messages and FaceTime have built-in functionalities that permit on-demand screen sharing, regardless of whether the screen sharing service is explicitly enabled in the system settings.

When using Messages, you can initiate screen sharing during a chat by clicking on the details of the conversation and selecting the option to share your screen. This feature facilitates seamless communication by allowing users to demonstrate applications or content directly, enhancing collaborative discussions.

Similarly, FaceTime offers a screen sharing feature that can be activated during a video call. Users can share their screens to show documents, presentations, or apps, allowing for a more interactive and informative conversation without needing to configure additional settings.

The other options do not provide the same level of integrated screen sharing capabilities. Safari and Mail are primarily focused on web browsing and managing emails, respectively, lacking the inherent screen sharing functionality. Photos and Notes focus on media organization and note-taking, while Maps and Calendar are oriented towards navigation and scheduling. Therefore, those applications are not designed for on-demand screen sharing.