Final answer:
The project milestone among the given options is 'Client approves website design.' This milestone reflects a key point where the project moves forward, usually from design to development or implementation.
Step-by-step explanation:
Among the options provided for a project milestone, d. Client approves website design is considered an actual milestone. A milestone typically represents a significant point of achievement in the project that can be easily identified and communicates progress. Client approval is a definitive and important stage in a project that often triggers the transition from the design phase to the next steps in the project, such as development or implementation.
The design process includes several steps, like prototyping, testing, and refinement. After testing and evaluating prototypes to assess the quality and functionality of the design, the team communicates the process and results to the stakeholders. If the design needs improvement, it can be refined based on feedback. The implmentation stage begins when you start putting the plans into action, creating the actual product based on the finalized design mock-ups.