When Technology Is Advancing So Quickly, Even a Patent From

When technology is advancing so quickly, even a patent from, say, two years ago may be _______
, because _______.

A) somewhat outdated; few firms are relying on the technology
B) completely outdated; no firm is relying on that technology any longer
C) irrelevant; inventors are only receiving a slice of the social value.
D) irrelevant; not every idea can remain under patent protection forever.