According to the Law of Definite Proportions

According to the law of definite proportions,

A) the ratio of the masses of the elements in a compound is always the same.
B) it is not possible for the same two elements to form more than one compound.
C) if the same two elements form two different compounds, they do so in the same ratio.
D) the total mass after a chemical change is the same as before the change.