The DTA account must be reduced by a provision account (valuation allowance)

a. forever. Same as accounts receivable and the estimate of the provision for uncollectible accounts.

b. if, based on all available evidence, it is 100% certain that some portion, or 100%, of the deferred tax asset will not be realized.

c. if, based on all available evidence, it is more likely than not that some portion, or 100%, of the deferred tax asset will not be realized.

d. If, based on all the available evidence, it is more likely than not to be 100%, the deferred tax asset will not be realized.