Sand Engaged in Operations at the Start of 2015 and Reported

Sand engaged in operations at the start of 2015 and reported $550,000 in pre-tax book income for the year. Tax depreciation for Sand exceeded book depreciation by $50,000. The tax rate for 2015 was 30%, and Congress had enacted a tax rate of 20% for the years after 2015.
-What is the deferred tax liability for Sand at December 31,2015?

A) $10,000
B) $15,000
C) $20,000
D) $40,000