Final answer:
Copyrights should be amortized over their useful life or legal life, whichever is shorter.
Step-by-step explanation:
Copyrights should be amortized over d. their useful life or legal life, whichever is shorter.
In general, for works created on or after January 1, 1978, the term of copyright is the life of the author plus 70 years after the author's death. If the work is a joint work with multiple authors, the term lasts for 70 years after the last surviving author's death. For works made for hire and anonymous or pseudonymous works, the duration of copyright is 95 years from publication or 120 years from creation, whichever is shorter.
Therefore, copyrights should be amortized over their useful life or legal life, whichever is shorter, in accordance with the duration of copyright protection.