Answer :
A or C are pretty much the same (as Linux is in the UNIX family). B depends on the version of Windows described. D is technically possible, but very difficult. The answer really comes down to cost (Linux is 'free' vs UNIX, which is licensed).
Answer:
in my experience with SAP R3, I suppose this is the best but you can use UNIX too.
Explanation:
This case shows the necessity of an integrated areas software which interact with all departments inside the company.