6 If tangible negative evidence exists, positive evidence may be necessary to overcome that evidence and to support a conclusion that a valuation allowance is not needed. Which of the following is not an example of such positive evidence? A carryback-carryforward period that is so brief that it would 1. limit realization of tax benefits 2. A strong earnings history exclusive of the loss that created the future deductible amount coupled with evidence indicating that the loss is an aberration rather than a continuing condition An excess of appreciated asset value over the tax basis of 3. the entity's net assets in an amount sufficient to realize the deferred tax asset 4. Existing contracts or firm sales backlog