Final answer:
The Pacific Ocean, being a vast body of water, is not a watershed; it is the recipient of water from multiple watersheds.
Step-by-step explanation:
The question asks which option is NOT an example of a watershed. A watershed is an area of land that drains or 'sheds' water into a specific body of water. The options given are a) Trinity River Basin, b) Cooper Creek River Basin, c) Lake Ray Roberts Watershed, and d) The Pacific Ocean. The correct answer is d) The Pacific Ocean. Watersheds typically refer to land areas, whereas the Pacific Ocean is a vast body of saltwater that encompasses entire watersheds within it, but is not itself a watershed.