When generating the resource management plan, which of the following should be considered FIRST?

A project manager has a project with staff in four different countries. When generating the resource management plan, which of the following should be considered FIRST?

A.
Reviewing holiday and vacation schedule with all team members.

B.
Getting the email address of all the employees.

C.
Locating each employee on the map in the office.

D.
Understanding the international country code of all the team members.