Renewable source means that it can never run out or run out in a long time. In this case the sun is expected to shine for about five billion years because of the high amount of hydrogen that is stored in its core. So the answer should be "The sun is continuously releasing energy". This answer is the best because there are many other renewable resources on earth that can cause pollution.
If density is greater, the object sinks. Saturn is mainly composed of the lightest two gases known, hydrogen and helium. It is the only planet in our solar system whose density is less than water