Consider statements I to IV about the escape speed from the surface of a planet (atmosphere ignored). Select the option that names every correct statement and no incorrect one.

• I. The escape speed does not depend on the mass of the body being launched.
• II. The escape speed from the moon's surface is less than that from the earth's surface.
• III. The escape speed from a planet's surface is √2 times the speed of a satellite orbiting just above that surface.
• IV. The escape speed from the earth's surface is about 7.9 km s⁻¹.