The answer to this is letter B. The planets are known to revolve around the sun. The sun is actually a start that helps provide the heat needed by earth so that it will not freeze over. Earth is the planet where we live but there are other planets that are available. Mercury is known to be the planet that is closest to the sun but the second planet Venus is the hottest because of its atmosphere.
The Earth is the third planet followed by Mars which is said to have had an atmosphere similar to what we had before although it is different now. After Mars, the following planets follow Jupiter, Saturn, Uranus, Neptune, and Pluto. Most of the planets come with moons but the earth only has one moon. There are still other things that are part of our current solar system.