Stu is a professional photographer. He likes to take pictures of industrial America - factories, warehouses, chemical plants, mines, ports and the like. Stu reproduces the photographs and sells them in a small gallery that he owns. He places the copyright symbol, O, on each photograph but he does not register his copyrights with the U.S. Copyright Office. One of Stu's friends, Dan, is a mechanical engineer and likes Stu's pictures and has purchased many of them. After studying at length one of the pictures he purchased from Stu - a picture of rock crushing equipment - Dan identified in the picture a simple modification to the equipment (which apparently had been done by the owner's employees) which could likely be patented. Therefore, he submitted a patent application for the equipment modification. The patent office has not made a decision with respect to issuing a patent to Dan. Stu has learned that Dan has applied for the patent and has taken the position that Dan had no right to patent the equipment modification because it appeared in Stu's copyrighted photograph. Which of the following statements is correct? A. Dan did not have the right to apply for a patent for the equipment modification because he did not invent it. B. Dan did not have the right to apply for a patent for the equipment modification because it was depicted in Stu's copyrighted photograph. C. Dan did have the right to apply for a patent for the equipment modification regardless of the fact that it was disclosed in a copyrighted photograph. D. Dan did have the right to apply for a patent for the equipment modification because Stu failed to register his copyrights with the U.S. Copyright Office.