TOGAF Part VII, Architecture Capability Framework recommends use of an ADM cycle for establishing an architecture practice. In this scenario which architecture would describe the organizational…

Application Architecture describes the individual applications and their relationships, not the organizational structure of a practice.

Business Architecture within TOGAF describes the organization's structure, processes, functions, and information, making it the appropriate domain to define the organizational structure for an architecture practice itself. It focuses on how an enterprise operates and its functional decomposition.

Data Architecture describes the structure of an organization's logical and physical data assets and data management resources, not organizational structure.

Technology Architecture describes the logical and physical software and hardware capabilities that support the other architectural domains, not organizational structure.

Transition Architecture describes an intermediate state towards a target architecture, focusing on changes, not a standing organizational structure.