The three categories of manufacturing costs comprising the total cost of work in process are direct labor, direct materials, and:

a) factory overhead.
b) direct expenses.
c) accounting salaries expense.
d) selling expenses.

A - factory Overhead

Explanation: Manufacturing costs are costs that a manufacturer incurres in getting the needed materials and costs incurred in converting the materials   into finished goods for sale.

Manufacturing costs includes the direct labour, direct materials and factory/manufacturing overheads

Manufacturing costs are mainly uncured by a manufacturing company that converts raw materials into finished consumable goods.