The correct answer is: Planets.
Mars, Earth, and Jupiter are all planets. A planet is a large celestial body that orbits a star and is not a star itself. Planets are typically round or oval in shape and are made of rock or gas. They have no light of their own, but reflect the light of the star they orbit.
The other options are incorrect. Cosmos is a word that refers to the universe as a whole. Orbits are the paths that planets and other objects follow around stars. Astronauts are people who travel into space.
