As a project manager, you notice that your team's progress has slowed down significantly due to a lack of timely responses from a key stakeholder, including an attempt to meet one-on-one with the stakeholder. Which of the following actions should you take to address this impediment?
Continue waiting for the stakeholder's response without taking any action
Adjust the project timeline to accommodate the delay caused by the stakeholder's lack of response
Escalate the issue to the project sponsor or higher management to help resolve the problem
Assign additional tasks to the team to compensate for the delay