Which of the following is mandatory in most software development projects?

A Communication Management Plan is a project-level artifact that guides stakeholder communication and, while recommended, is not universally mandated by software engineering standards or methodologies.

A Disaster Recovery Plan addresses business continuity and operational resilience and is an IT operations concern, not a standard deliverable of the software development lifecycle.

A test plan is a required artifact across virtually all software development methodologies - including waterfall, iterative, and Agile - because it establishes how the software will be verified against its requirements. It defines what will be tested, how, by whom, and what constitutes a pass or fail, making it essential for quality control and compliance with standards such as ISO/IEC/IEEE 29119.

A Procurement Plan is only applicable when a project requires sourcing external products or services, and many software projects are completed entirely with internal teams, making it non-universal.