Which innovation was fully developed in Germany related to theater?

The revolving stage, often referred to as the "turntable stage," is an innovation that was fully developed in Germany and revolutionized theatrical performances. This innovative design allows for seamless scene transitions, enabling multiple settings to be presented without the need for extensive set changes that could disrupt the flow of a performance. The revolving stage creates dynamic movement and enhances the visual storytelling experience by allowing actors to occupy different spaces on stage without ever leaving the audience's view.

Its implementation has significantly impacted stagecraft and has been adopted widely in theater productions around the world. This innovation exemplifies how engineering and design can blend with the performing arts to improve the overall spectacle of theater. Other options, while related to theater as well, did not originate or become fully developed in Germany in the same significant, transformative way as the revolving stage.