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 individual software applications and their interactions, not the organizational structure of a practice.

When establishing an architecture practice, the ADM can be used to define the capability itself. The organizational structure, roles, responsibilities, governance, and processes of the architecture practice are all elements that define how the business of architecture is conducted, which are core components of the Business Architecture domain.

Data Architecture describes the structure and management of an organization's data assets, not the organizational setup of its architecture team.

Technology Architecture describes the underlying hardware and software infrastructure that supports applications and data, not the human and organizational aspects of a practice.