What should the project manager do first?

In the beginning of project execution, the project manager finds out that a key resource will be unavailable for two weeks which could cause a delay to the schedule.

What should the project manager do first?
A . Assign the tasks to another resource, and ask the resource to work double shifts
B . Update the schedule to reflect the project’s changes in duration
C . Ask human resources (HR) for a replacement, and update the nsk register
D . Update the resource management plan and resource allocation chart accordingly

Answer: D