What is one capability of mobile phones in relation to voice commands?

Mobile phones have integrated voice recognition technology that allows users to perform various actions using simple voice commands, making them highly convenient. One of the key capabilities in this area is the ability to perform tasks like setting alarms through voice activation. By saying a specific command, a user can easily create and manage alarms hands-free, demonstrating the functionality and versatility of voice commands in enhancing user interaction with mobile devices.

The other options do not align with the core function of voice command capabilities. While playing music automatically can be part of some music apps, it typically requires additional interaction from the user to select and start the music. Displaying advertisements and writing messages automatically do not directly relate to the voice command feature, as these actions either don't rely on voice activation or require user input beyond basic commands. Thus, setting an alarm through voice commands represents a direct application of voice technology in mobile phones.