Which of the following is an iterative software development methodology that focuses on achieving customer satisfaction by delivering the software early in the process and welcoming changing requirements from the customer, even late in the process?

The Spiral model combines iterative development with systematic risk assessment, focusing on risk management and project planning rather than customer satisfaction and flexibility. While it allows for iterative processes, it is not primarily centered on welcoming changing requirements late in the development cycle like Agile.

The Waterfall model is a linear and sequential approach to software development that follows distinct phases without returning to previous steps. It does not accommodate changes easily once a phase is completed, making it contrary to the Agile methodology that promotes responsiveness to evolving customer needs.

Lean software development focuses on optimizing efficiency and minimizing waste throughout the development process. Although it shares some principles with Agile, such as iterative improvements, Lean does not inherently emphasize customer satisfaction through early delivery and accommodating late changes as Agile does.