Questions: According to the author, the theatre is probably the most common and well-known arrangement today.

The answer is D: proscenium.

Explanation for each option:

A. Black box: A black box theatre is a simple, unadorned performance space, typically a square room with black walls and a flat floor. While versatile and popular in experimental theatre, it is not the most common or well-known arrangement.

B. Thrust: A thrust stage extends into the audience on three sides and is connected to the backstage area. While it offers a unique viewing experience, it is not as common as the proscenium stage.

C. Arena: An arena stage, also known as theatre-in-the-round, is surrounded by the audience on all sides. This arrangement is less common than the proscenium stage, especially in traditional theatre settings.

D. Proscenium: The proscenium stage is the most traditional and widely recognized theatre arrangement, characterized by a large arch (the proscenium arch) that frames the stage and separates it from the audience. This setup is prevalent in many theatres around the world, making it the most common and well-known arrangement.