Answer:
D.
Step-by-step explanation:
A utility patent is a type of patent that is used to confer the copyright of new inventions. Utility patent is the most common of all types of patents. It is also known as 'patent for invention.' This patent right enables the inventors to commercialize the right of producing the invention under their own names. This patent also disables others to manufacture or sell the invention with their own names.
In the given case, the class has invented a 'self-cleaning reptile tank' which should be copyrighted under the 'utility patent' as it is a new invention.
Thus option D is correct.