If a Firm Cannot Use Available Tax Shields in the Year

If a firm cannot use available tax shields in the year those tax shields are available,what happens to the benefits of those tax shields?

A) The benefits are not lost or reduced because they can be used to offset or reduce future taxable income.
B) The benefits of the tax shields are always lost and cannot be taken advantage of in future years.
C) The benefits are allocated to other firms in the industry.
D) The benefits provided by the tax shields are either lost because the tax shield benefits expire or are reduced because the benefits are taken in later years.