Answer:
b.
Step-by-step explanation:
Based on the information provided within the question it seems that the principle that best explains Sam's decision is the sunk cost fallacy. This term refers to a cost that cost that has been incurred but cannot be recovered or changed. Usually these costs were known before being incurred and do not affect future costs for the individual or business. Which is basically what Sam is mentioning when talking about all the money that he put into his already owned car, which influenced his decision on whether or not to buy a new car.