Which discipline involves applying technical and administrative direction to document functional characteristics of a configuration item?

The discipline that involves applying technical and administrative direction to document the functional characteristics of a configuration item is configuration management. This process ensures that the integrity and consistency of a product's performance, functional, and physical attributes are maintained throughout its lifecycle. Configuration management includes identifying, controlling, and documenting changes to the configuration items, which can consist of software, hardware, or any other components involved in a project.

This discipline is crucial in environments where changes are frequent, particularly in agile methodologies, as it helps teams to manage updates efficiently while keeping track of what has been altered and how these changes impact the overall project. The activities associated with configuration management provide a structured approach to maintain the state of components, ensuring that project stakeholders have access to accurate and current information regarding the system's configuration.

In contrast, other options such as quality assurance focus on ensuring that processes are followed to maintain product quality, change management deals with how changes in a project are systematically managed, and version control specifically refers to the tools and processes used to manage changes to documents, programs, and other collections of information.