John Morse corporation buys a van for $16,000. The estimated life of the van is four years. The residual value of the van is $4,000. After two years, the van is sold for $8,000. What was the difference between the book value and the amount received from selling the van if John used the straight-line method of depreciation?
A.$4,000
B. $12,000
C. $8,000
D. $2,000