Project Metrics week 7 DQ

I need help with below. No plagiarism, no work cited from Wikipedia. Must cite all references, APA style, due 10/12/16 Minimum of 400 words.

An equipment manufacturer has purchased large quantities of steel plate for its five machines as well as for machines for other customers. By ordering in large quantities, the manufacturer received a substantial price break. What is the earliest time the manufacturer should take credit for the steel plate?

1.        When ordered

2.        When received

3.        When paid for

4.        When withdrawn from inventory

5.        When installed

Once you have selected your answer, explain why you chose that answer and elaborate on what could go wrong ordering large quantities of steel plates?