Consider the diagram of an architecture development cycle.

The Architecture Development Method (ADM) is the core process of TOGAF which outlines a method for developing and managing the lifecycle of enterprise architecture. Considering the phases of the ADM, the item labeled as '2' in the provided architecture development cycle diagram likely corresponds to the 'Architecture Change Management' phase, which is responsible for providing ongoing architectural oversight and guidance to ensure that the implementation remains aligned with the architecture defined in the previous phases. This includes managing changes to the architecture in a controlled manner as the implementation progresses and ensuring that the architecture continues to meet the business needs.