Which element is NOT available in the Optimized Design Experience?

The Optimized Design Experience is a new user interface for SAP Analytics Cloud that simplifies and enhances the story design process. The Optimized Design Experience introduces some new elements and tools, such as Data Analyzer, Point of Interest, Time Series chart, etc. However, it also removes some elements and tools that are available in the Classic Design Experience, such as Grid page, Explorer, Digital Boardroom, etc. Therefore, the correct answer is Grid page, as it is the element that is not available in the Optimized Design Experience.