Which of the following is an example of a utility patent?

A utility patent protects new and useful processes, machines, articles of manufacture, or compositions of matter, or any new and useful improvement thereof. The mousetrap is a classic example of a utility patent because it involves a functional device designed to solve a specific problem—catching rodents. Its invention improves on mechanical efficiency or effectiveness in achieving that goal, satisfying the criteria for patentability.

In contrast, shoe designs, the shape of a phone, and the shape of an auto wheel typically pertain to design patents, which protect the ornamental design of a functional item rather than its utility or function. Design patents focus on the aesthetic appearance rather than the functional aspects, distinguishing them from utility patents.