The Value of Goods Added to a Firm's Inventory in a Certain

The value of goods added to a firm's inventory in a certain year is treated as

A) consumption,since the goods will be sold to consumers in another period.
B) saving,since the goods are being saved until they are sold in another period.
C) investment,since GDP aims to measure the value of the economy's production that year.
D) spending on durable goods,since the goods could not be inventoried unless they were durable.