What we know by the textbook is that E = is the equation of physics. Simplified, The equation is: "Energy = mass times the speed of light squared.". Our knowledge on physics and that equation understandment determines that A is the correct choice.
E represents units of energy, m represents units of mass, and c2 is the speed of light squared, or multiplied by itself
So I THINK that A is the right answer but i may be wrong.
I hope this helped :)
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