Question

which statement best describes the concept of Einstein's E=mc2?

Answer 1

Could you be more specific?

Answer 2

energy = mass * the speed of light squared

This concept tells you that is you take any mass and accelerate it to the speed of light squared it will turn to pure energy and the mass will cease to exist.

This makes the existence of the universe seem possible because it implies you can exchange energy and get mass back from it. SO if there was no solar system or planets in the beginning and only pure energy, the energy could become mass.

In nuclear bombs just the opposite occurs, a mass is converted into energy and after accounting for all byproducts and heat, there is actually a loss of mass. Compare that to a chemical explosion where you have the same amount of mass before the explosion as after, when you add all the CO2 , H2O and other gases back into the mass