Which of the following is an example of collusion?

Which of the following is an example of collusion?
A . An employee includes a faked receipt in his expense claim, and the claim is signed by the employee’s manager.
B . A vendor inflates the price of an item and remits a portion of the excess to the purchasing manager.
C . A vendor sends a duplicate invoice with a new invoice number, and the accounts payable system fails to detect the duplication.
D . An employee works with the IT manager to develop a program for identifying duplicate invoice payments.

Answer: B