The correct answer is: A. systems analysts.
File specification books are created primarily for the use of systems analysts. Systems analysts are responsible for designing and developing information systems. They need to understand the data that will be stored in the system and how it will be used in order to design the system effectively. File specification books provide this information in a clear and concise format.
Option B is incorrect because programmers do not need to know the details of the data that will be stored in the system. They only need to know how to access the data and how to manipulate it.
Option C is incorrect because operators do not need to know the details of the data that will be stored in the system. They only need to know how to load and unload data from the system.
Option D is incorrect because managers do not need to know the details of the data that will be stored in the system. They only need to know how the system will be used and how it will benefit the organization.
Option E is incorrect because file specification books are created for the use of systems analysts.