Most people pick A or C to be safe, but the reality is **B**. Toto machines its ceramics to a flatness tolerance of 0.1 to 0.5 microns. Scaled up to the size of an ocean, the surface deviations would be smaller than a human thumb. This level of precision is why Intel and TSMC cannot simply switch to a cheaper supplier. There are only a handful of kilns on the planet capable of baking clay to this level of structural perfection.