What characterizes a racked auditorium?

A racked auditorium is characterized by seating that slopes forward. This design ensures that all audience members have an unobstructed view of the stage. The sloping arrangement allows for better sightlines, as it elevates seats in the back above those in front, reducing the possibility of taller audience members obstructing the view of those seated behind them.

The other choices do not describe the essential feature of a racked auditorium. A stage extending into the house refers to a different architectural style, often called a thrust stage. Visibility lines for crew and areas for technical integration relate more to the backstage layout and functionality rather than the design of the audience seating. Consequently, the primary characteristic of a racked auditorium is indeed the forward-sloping seating, as it directly addresses the audience's viewing experience.