Examine the following statements on the line and staff and identify the ones which are true.
1. Line and staff concept originated from Military.
2. Line decides and staff assists.
3. Personnel role is performed both by line and staff.
4. The Personnel Department's role is a staff function.

A. Both 2 and 4

B. 1, 2 and 4

C. 2, 3 and 4

D. All of the above

Answer: Option D