Donny Robert had borrowed money from a credit union to purchase a car, and the credit union had required a security interest against the car, which it registered under the Personal Property Security Act. As well, Danny's father guaranteed the loan. Three months later, Donny decided to go back to school, and he had to sell the car to do so. Donny returned to the credit union and, at his request, the credit union gave up the security it had against the vehicle, knowing that it still had the loan guaranteed by Donny's father.

Required: Explain why this change was in Donny's best interest.