Granger Company Makes Portable DVD Players

Granger Company makes portable DVD players. In its inventory, Granger found 200 DVD players that had become obsolete. Each DVD player has a cost of $100. Granger can upgrade these DVD players for $15 each after which they can be sold at a cost of $40 each. Granger has also received an offer to sell the DVD players, as is, for a total of $4,000. What is the total amount of sunk cost?

A) $3,000
B) $4,500
C) $8,000
D) $20,000