Note: You only have 3 attempts to answer this question.?

1 and 3 are definitely true. you can't use fractional coefficients and let's say you have H2O which is water...if you change the subscript 2 to a 1, you'll have OH which is hydroxide (not water)...but im not sure about the other ones (2 and 4) sorry!! to take a guess tho, im pretty sure 2 is also true because when you balance equations, it makes it so that you end with the same amount of atoms as you started with which goes along with the conservation of matter...4 i just have no idea....but since you have 3 tries, just try 4 lol