RT-CDP - What is the number of environments (dev, staging, production) that comes with the RTCDP license?
Here we are talking about just one environment, but multiple sandboxes.
Check the Product Description for details: https://helpx.adobe.com/legal/product-descriptions/real-time-customer-data-platform.html
Sandboxes. Real-time Customer Data Platform includes up to 5 Sandboxes.