Answer: Post Purchase Behavior
Explanation:
At the Post-purchase behavior stage, the customer has already bought and received the goods they ordered. They will now assess it to see if it meets their quality standards to see if they can keep the goods and continue to use the vendor or return the goods and look for another.
This is what Whirlpool does here by rating the parts that were purchased and notifying the suppliers of said parts so that they fix things. If they do not, Whirlpool would find another vendor. They are therefore at the post purchase behavior state.