Answer:
Id have to go with B
Step-by-step explanation:
Lets go through our options real quick
D. You should never pick a side and team up on someone in a professional environment, so this one is a no go.
C. You cant really ask how they will prevent future conflicts if there still in a conflict themselves.
A. While pulling the 'rules' card could definitely work to breaking it up fast; it could also leave lasting dissent between the two workers since they couldn't work out their argument.
B. This one makes the most sense to me. Getting both sides of their stories and getting them to hear each other's reasoning would be an important first step in defusing a disagreement.