Disciplined Agile (DA) is an agnostic hybrid approach that draws upon various ideas, principles, and practices from multiple agile and lean methodologies, including Scrum, Kanban, Extreme Programming (XP), Lean, and others. It does not adhere strictly to one methodology but instead provides a toolkit that allows teams to tailor their ways of working based on their specific context, objectives, and constraints. Options B (Agile), C (Iterative), and D (Lean) are more specific frameworks or approaches, whereas Disciplined Agile explicitly combines multiple methodologies in an agnostic manner.