Fuller Industries is considering replacing a machine that is presently used in its production process. Which of the following amounts represents a sunk cost? Replacement Old Machine Machine Original cost Remaining useful life in years $55,000 $45,000 5 5 Current age in years 5 0 Book value $30,000 Current disposal value in cash $10,000 Future disposal value in cash (in 5 years) $0 $0 Annual cash operating costs $7,000 $4,500 OA. $45,000 OB. $10,000 C. $55,000 D. $30,000