Which of the following are key stakeholders in a temporary Project Office?

Which of the following are key stakeholders in a temporary Project Office?
1. Organization Portfolio Office
2. Business as usual staff
3. Suppliers to the project
4. Project Board members

A.
1, 2, 3

B.
1, 2, 4

C.
1, 3, 4

D.
2, 3, 4