Please help me whoever gets the answer right first will get brainliest

I believe its this

Step-by-step explanation:

you can see the step by step in the attached image as well as the result

the law of definite proportions states samples of a compound will always contain the same proportion of elements by mass. in other words, a given compound will always contain the same elements in the same proportions by mass.the law of multiple proportions states when two elements combine with each other to form more than one compound, then the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.