Which external monitor is NOT mentioned as using CR PLAY?

The choice indicating the soundboard is correct because it is not listed among the external monitors that utilize CR PLAY. Typically, external monitors like MDR, External 1, and External 2 are specifically designed to integrate with CR PLAY for enhanced functionality, allowing for features like real-time monitoring and audio feedback. The soundboard, while an important component in audio setups, does not fall under the category of external monitors that are designed to work specifically with CR PLAY, making it the distinct option in this context. It highlights the importance of knowing the specific functionalities and compatibility of various equipment in an API setting.