You are a project manager familiar with plan$-$driven project management and you are seek to better understand agile project management. Which one of the following is NOT a principal of the Agile Manifesto:

a$.$ Agile is an approach that operates withs six stages: requirements, analysis, design, coding, testing, and deployment.

b$.$ Self$-$managed teams help develop the best architectures, requirements, and designs.

c$.$ People representing business and development teams must work together constantly.

d$.$ Project team comprised of motivated people must be engaged in the project; support and trust must be extended to the project team.