Answer: option B
Explanation:
Since they are indictors of potential work place violence ,they can be managed.
I am picking the word indicator, becasue this is to preinfom someone or something of a potential circumstance to happen over a period of time if the case maybe. This is an indictor to pre-inform to make known that something will happen. Then it can be managed, work place violence can be managed once there exist a sign such as the passage related to indicator. So option B potentially is the right answer.