Which of the following must be shown on a condominium plat?

The correct choice is the requirement to show the dimensions of each unit's vertical boundaries on a condominium plat. This is crucial for distinguishing individual units within a condominium structure, which may be stacked one atop the other. The vertical boundaries provide clarity on the specific space ownership and usage rights of each unit owner, which is essential for property management, whether for maintenance responsibilities or for determining limits in the event of modifications or repairs. Such details are mandated in condominium declarations and contribute to the overall understanding and organization of shared spaces within the development.

The other aspects, such as the name of the developer, the names of all owners, and the location of local amenities, while potentially important for various planning or legal purposes, are not typically required to be detailed on a condominium plat itself. The primary focus of the plat is on the geometry and delineation of the property units, which is where the dimensions of vertical boundaries are paramount.