If Inventory Investment During a Year Was Minus $6 Billion

If inventory investment during a year was minus $6 billion, producers must have

A) produced only $6 billion of new capital assets during the year.
B) sold $6 billion more goods and services during the year than they produced.
C) added goods valued at $6 billion to their stock of unsold goods and raw materials.
D) produced new capital assets that exceeded the depreciation allowance by $6 billion.