A corporation had accumulated temporary book-tax differences of $100,000 as of the beginning of the tax year due to a net operating loss in the prior year and that prior year's tax rate was 35% thus accordingly it had a deferred tax asset of $35,000 as of the beginning of the year also. Due to the fact that the tax rate changed to 21% in the subsequent year - what happened to the book income? A. It increased by $21,000 B. it decreased by $14,000 C. It decreased by $21,000 D. No change E. It increased by $14,000