Which one of the following is false regarding kickbacks?

a. A kickback is an illegal payment made by a customer to a supplier so that the customer receives preferential treatment from the supplier.

b. A kickback is an illegal payment made by a supplier to a customer so that the supplier receives preferential treatment from the customer.

c. A kickback is typically paid in the form of cash or merchandise but can also be paid in the form of stock options. 

d. A kickback is a type of bribery. 

e. Two of the above (a–d) are false.