Manufacturers usually classify inventory into all the following general categories except:

a. work in process

b. finished goods

c. merchandise inventory

d. raw materials

c. merchandise inventory

Explanation:

Merchandise inventory is related to finished goods that have been purchased and are intended to be resold for a profit.

Since the question refers to manufacturers (companies that produce their own product), the only general inventory classifications applied are work in process, finished goods and raw materials.

Therefore, the answer is c. merchandise inventory.