Which of the following statements is not true of the law of
trademarks in the United States?

(d) Trademarks are valid indefinitely until they are actually
abandoned or the company allows the trademark to lose its
distinctiveness. Answer (a) is not chosen because trademarks
can protect many distinctive things such as shapes, packaging, or
graphic designs. Answer (b) is not chosen because a company
must take steps to keep the trademark distinctive or it can lose it
through others’ common usage. For example, elevator was once
a trademark which has since been lost. Answer (c) is not chosen
because although a company may register a trademark to better
protect its legal rights, it may still receive protection without
registering it by proving the facts.