Which statement accurately describes the nature of a utility patent?

A utility patent is specifically designed to protect the functional aspects of an invention, distinguishing it from other types of patents. This type of patent grants the inventor exclusive rights to manufacture, use, sell, and distribute the invention for a specific period, typically 20 years from the filing date. The focus is on how the invention works, what it does, and the processes involved, which can cover a wide range of innovations such as machines, articles of manufacture, compositions of matter, or any new and useful improvements thereof.

The other choices do not accurately describe the characteristics of a utility patent. A utility patent does not solely cover design aesthetics; that aspect is addressed by design patents. The validity period of a utility patent is not indefinite, as it expires after 20 years unless maintenance fees are not paid. Additionally, a utility patent can be filed independently; there is no requirement for a design patent to be granted first. Therefore, option A is the accurate description of the nature of a utility patent.