Answer:
(C) Janitorial, Welding, HR, Data Svcs, Assembly
Explanation:
Question: If the step-down method is used in this case, which sequence of allocations is not valid?
The step method will allocate a portion of a service department to others service department cost thus, increasing the cost of these.
In this case cost from Janitorialo will go into HR and Data serivces.
Is important to understand that these method have as goal to allocate their cost into production department. The production department receive cost from the service department. They do not allocate into service. Never.
Having said that statement; the conclusion is that option C is incorrect as it is doing a distribution of produciton department into service department.