One essential difference between a patent and a copyright as two different mechanisms of intellectual property (IP) protection is that:

A.A patent lasts only for twenty years but a copyright can last indefinitely.

B.Unlike acquiring a patent, obtaining a copyright does not require any application or registration.

C.A patent could also be enforceable on a written work, provided the inventor chose to file an application to that effect.

D.A patent only applies to a product and a copyright to a process.