Which of the following is not categorized as a line function?

Human resources functions are typically considered support functions rather than line functions. Line functions are those that directly contribute to the core business activities and are responsible for generating revenue, such as inventory management, warehouse operations, and shipping and receiving. Human resources, on the other hand, plays a key role in recruiting, training, and managing employees, which supports the organization but does not directly engage in producing goods or services. Therefore, while essential for the overall operation of a business, human resources does not fit the definition of a line function.