According to the given question, the part of the conversion factor that should go in the green box is the Avogadro's number, which is 6.02x10^23.
It means the correct answer is A.
In the red box that is above the green box, you should put 1 mole Mg.
In the red box that is next to it, you should put 24.30 grams Mg and in the one that is below, 1 mole Mg.
