Which item would you find used in securing scenery to the stage floor?

The correct choice is Boss Plate, which is indeed used to secure scenery to the stage floor. A Boss Plate is a heavy metal plate that can be anchored to the stage surface, providing stability for various stage elements such as flat pieces, set props, or other scenery. By using Boss Plates, productions ensure that larger scenery elements stay in place during performances, especially in situations where movement or vibrations can occur, such as during quick exits or entrances.

In comparison, the other items mentioned do not serve the same purpose. A Bell Board is typically used for elevating or managing a curtain or backdrops. Blacks refer to black drapes or curtains that are often used for masking and can help frame the stage space but do not function as anchors for scenery. Breakaway is a term often associated with props or scenery designed to dismantle or fall apart for effect, which means it’s specifically designed to move rather than secure elements in place. Thus, the role of the Boss Plate in securing scenery makes it the most suitable choice for this particular function.