This question includes four answer choices: A. definite volume, highest molecular motion, highest kinetic energy B. indefinite volume, least molecular motion, highest kinetic energy C. definite volume, least molecular motion, lowest kinetic energy D. definite volume, no molecular motion, lowest kinetic energy Solids do not have the highest molecular motion (on the contrary they have the least molecular motion), so you can discard option A. Solids have a definite volume and the highest kinetic energy (given that they have the least molecular motion), so you discard option C. Molecules always have a vibrational motion, so you discard option D. Option C, have only characteristics that correctly describes a solid: definite volume, least molecular motion, lowest kinetic energy. Therefore, the answer is the option C.