Final answer:
Project milestones should be based on an objective evaluation of working systems, as this ensures they are grounded in the project's practical progress. Industry standards may guide, but milestones require customization to the project's specifics. The correct option is C.
Step-by-step explanation:
Project milestones should be based on c) an objective evaluation of working systems. This approach ensures that milestones are practical, achievable, and rooted in the reality of the project's progress.
While project manager preferences and theoretical calculations may inform the process, the core milestones should reflect tangible achievements in the project lifecycle. Industry standards can offer guidance, but they must be adapted to the specifics of the given project.
Establishing milestones based on an objective evaluation ensures that they serve as effective tools for measuring progress, identifying potential issues early, and facilitating stakeholder communication. A well-defined milestone could be the completion of a critical phase of software development or the successful testing of a prototype.