Income tax expense $($i$.$e$.,$ the provision for income taxes$)$ equals:

a$.$ Current taxes payable $+$ the increase in deferred tax liabilities $-$ the increase in deferred tax assets.

b$.$ Current taxes payable $-$ the increase in deferred tax liabilities $+$ the increase in deferred tax assets.

c$.$ Current taxes payable $-$ the increase in deferred tax liabilities $-$ the increase in deferred tax assets.

d$.$ Current taxes payable $+$ the increase in deferred tax liabilities $+$ the increase in deferred tax assets.