D. Advise the client of the impact of the change.
Before making any decisions or taking actions, it is crucial for the PM to communicate transparently with the client about the implications of the requested change. This involves:

1. Analyzing the impact: The PM should thoroughly assess the impact of the change, not just on the schedule but also on other areas such as cost, resources, quality, and risk.
2. Quantifying the impact: The PM should provide the client with specific details on how the change will affect the project, such as the two-week delay in the critical path, as well as any potential cost increases or resource constraints.
3. Explaining the consequences: The PM should clearly explain the consequences of the change, such as potential delays in the project completion date, increased costs, or any other relevant implications.

By advising the client of the impact, the PM can ensure that the client fully understands the ramifications of the requested change before making an informed decision. This transparency and open communication can help manage expectations and align stakeholders.
The other options may be premature or incomplete:
A. Compressing the schedule: While this may be an option, it should not be done without first consulting with the client and fully understanding their priorities and willingness to accept potential trade-offs or risks associated with schedule compression.
B. Cutting scope: Similar to schedule compression, reducing scope may be a viable option, but it should not be done unilaterally without consulting the client and sponsor first.
C. Consulting with the sponsor: While consulting with the sponsor is important, the immediate priority should be to advise the client, who requested the change, of the impact before seeking guidance from the sponsor.