Which of the following is true about trademarks?

The chosen option highlights an essential requirement for trademark registration. Trademarks must be unique, which means they cannot be identical or confusingly similar to trademarks that are already registered or in use by others in the relevant market. This uniqueness is critical because it helps to distinguish the goods or services of one entity from those of another, preventing consumer confusion.

The requirement for uniqueness ensures that trademark registrations maintain their purpose: identifying and distinguishing products. If a trademark is not unique, it could lead to consumer confusion regarding the origin of goods or services, undermining the protection afforded to the trademark owner. This foundational principle is central to trademark law and creates a layer of protection for both consumers and businesses.

The other options do not accurately reflect trademark laws: trademarks do require periodic renewal, and while they may last indefinitely as long as they are in use and maintained, they are not valid indefinitely without renewal. Furthermore, trademarks provide protection beyond identical usage; they can also protect against uses that may cause confusion, even if the marks are not identical.