问一个FSA的题目,有原题,谢谢

FSA page 204 15题:

An analyst gathered the following information about a company:

Taxable income is $40,000;          Pretax income is $50,000;            Current tax rate is 50%;         Tax rate when the reversal occurs will be 40%;

What is the company's deferred tax liability at the end of year 1?

A $3,500     B $4,000     C $4,500     D $50,000

Answer: B

explanation: The tax rate that should be used is the expected tax rate when the liability reverses. The deferred tax liability will be $10,000×40%=$4,000

我的疑问是,题目为什么说是40%的税率呢?如果公司始终增加投资,累计折旧不断增加,则DTL是不会reverse的啊,那么为什么要用40%的税率呢?

谢谢指教!