The correct answer is: B. inventory file
A class 2 materials transaction is a movement of materials from one production department to another. This type of transaction does not require updating of the cost center file or the work order file because the cost center and work order information are already captured in the inventory file.
The cost center file is a database that stores information about the costs associated with each production department. The work order file is a database that stores information about the work orders that are being processed in each production department.
The inventory file is a database that stores information about the materials that are available in each production department. When a material is moved from one production department to another, the inventory file is updated to reflect the new location of the material.
The cost center file and the work order file are not updated because the cost center and work order information are already captured in the inventory file. The inventory file is the only database that needs to be updated when a material is moved from one production department to another.