Which of the Following Statements Is True About Planner/buyers

Which of the following statements is true about planner/buyers?
I. Planner/buyers handle more components than planners do.
II. Planner/buyers issue material releases to suppliers.
III. Planner/buyers establish supplier delivery priorities.
IV. Planner/buyers negotiate prices with suppliers.

A) I and II are true
B) II and III are true
C) III and IV are true
D) I, II, and III are true
E) II, III, and IV are true.