William is a sole proprietor who sells widgets he crafts on a 3-D printer. Which of the following costs is included in his cast of goods sold?

1) Payments to an outside contractor who diagnoses and fixes technical difficulties when the printer breaks down.

2) Cost of plastic used to make the widgets.

3) Payments to the graphic artist who designed the logo for his website.

4) Cost of obtaining a patent for the Useful Widget 3.0