Traditional Japanese pagodas are remarkably resilient to seismic activity, with records showing that only a handful have collapsed during earthquakes over the past millennium. This structural durability is primarily attributed to a design element known as the *shinbashira*, a massive central wooden pillar that runs the height of the tower. Unlike the load-bearing columns found in Western architecture, the shinbashira carries none of the building's weight. Instead, it is suspended down the center of the structure, either resting on a stone base or hanging from the top story.
Each individual story of the pagoda is built to slide independently of the others. During an earthquake, these stories sway in opposite directions, acting as a series of counterweights. This out-of-phase movement is made possible because the wooden floorboards of each story are crafted with wide central openings that do not contact the shinbashira. When the ground shakes, the stories shift laterally, but their internal edges eventually collide with the central pillar. The shinbashira restricts the maximum displacement of each story, ensuring that the lateral shifting does not exceed the structural limits of the timber joints. Consequently, the tower remains standing because the shinbashira prevents the individual stories from sliding too far off-center.
According to the passage, the out-of-phase movement of the pagoda's individual stories is made possible by which of the following design features?
- The presence of wide central openings in the floorboards that prevent them from touching the central pillarCevap
- BThe massive load-bearing weight that the shinbashira transmits from the top story down to the stone base
- CThe rigid timber joints that lock the stories together to prevent them from shifting laterally
- DThe immediate collision of the floorboards with the central pillar as soon as seismic activity begins