Your answer would be d. The farther away a planet is, the colder it becomes and the closer a planet is, the hotter/warmer it becomes. For example, Mercury is extremely close to the sun, making temperatures on it super high while planets that are farther away like Saturn are colder since they are so far away. There are planets who are in the Goldilocks Zone as well. The Goldilocks Zone is the perfect distance from the Sun(or any star if you apply this to other solar systems) therefore, creating the perfect temperature suitable for life. There are other factors as well but that is slightly unrelated to this question.
