What is a rock?

A rock is a solid object that is made from pieces of the earth. You decide if something is a rock based on its composition and its origin. Rocks come in a variety of shapes, sizes, and compositions. After careful consideration of the options on the probe, I believe that all of the options are rocks. At first, I ruled out the man-made objects, but then second-guessed that decision: despite being man-made, these objects still originate from pieces of the earth. I was also quick to rule out objects that were not round or circular, but then decided that a rock does not have to be round or circular to be a rock. My reasoning points to my original definition of a rock -- it originates from pieces of the earth and can be a variety of compositions, sizes, and shapes.