In severe cases, new schedule duration estimates with new forecasted start and finish dates are needed. In these instances, it is an example of using the control schedule process. Control schedule process is a method of monitoring the status of the project to update project progress and deal with the changes to the schedule baseline. It is concerned with:

Determining the current status of the project

Influencing the factors that create schedule changes

Determining that the project schedule has changed

Managing the actual changes as they occur

Control schedule is a component of the Perform Integration Change Control process.

Answer option D is incorrect. The activity resources would only address the addition or replacement of resources needed to complete the project work.

Answer option B is incorrect. This is a tempting choice, but new schedules are a part of the control schedule process.

Answer option A is incorrect. Develop schedule is not the best choice for this question.