Stephen is restoring a car and has already spent $$4,000$ on the restoration. He expects to be able to sell the car for $$5,800.$ Stephen discovers that he needs to do an additional $$2,400$ of work to make the car worth $$5,800$ to potential buyers. He could also sell the car now, without completing the additional work, for $$3,800.$ What should he do$?$

He should sell the far now for $$3,800.$

He should keep the car since it wouldn't be rational to spend $$6,400$ restoring a car and then sell it for only $$5,800.$

He should complete the additional work and sell the car for $$5,800.$

It does not matter which action he takes since the outcome will be the same either way.