Answer: The correct answer is "B. disturbance handler".
Explanation: When a customer service manger works to defuse a situation with an irate customer is taking on disturbance handler managerial role.
Clearly, when a customer service manager is presented with a situation of an unsatisfied customer who is furious about certain causes and this must calm him down in order to effectively solve his problem, he must use a managerial role of disturbance handler.