I don't understand how they are finding the deferred tax liability of 4,000.

In year 1, Casa Corp. has depreciation expense for income statement purposes of $20,000. The depreciation deduction on the tax return was $30,000. The enacted tax rate is 40%. Casa's pretax income for the year was $100,000, and its taxable income was $90,000. If this is the only difference between pretax income and taxable income, the journal entry to record tax expense for the year would include which of the following entries? (Select all that apply.) credit deferred tax liability of $36,000 debit tax expense of $40,000 credit deferred tax liability of $4,000 credit taxes payable of $36,000 debit deferred tax asset of $10,000