Sullivan Company bought a copyright for $45,000 on January 1, 2013, at which time the copyright had an estimated useful life of 15 years (until December 31, 2027). On January 5, 2016, the company determined that the copyright would expire at the end of 2021. What would be the adjustment to Sullivans beginning retained earnings for 2016?
A)	$ 0.
B)	$6,000.
C)	$4,000.
D)	$7,200.