Concept:The planets in our solar system are arranged in order of increasing distance from the Sun. The planet closest to the Sun is Mercury.Explanation:Mercury is the smallest planet and orbits the Sun at an average distance of about 57.9 million km. Its orbital period is only 88 Earth days, making it the fastest planet. Due to its proximity to the Sun, it experiences extreme temperature variations (from very hot to very cold) and has no moons or rings. The other options: Saturn (6th), Uranus (7th), and Jupiter (5th) are all farther from the Sun than Mercury.Answer:Mercury (Option B) is the correct answer.