You just have to compare the ratio you're given to the answers and see if the ratios from the answers match up to the ratio you were given. The reason C is the answer is because if you divide by 3 in the ration, it is the same as the ratio you were given, 7:3
Since 40 acres of land produces 600 bushels so the bushels produced by 1 acres of land is 600/40=15 So bushels produced by 75 actes of land = 75×15=1125 bushels
