5.3 is 5 3/10
5 1/3 is 5.3333333333333...
Two ways of looking at this
1) Which is bigger, 5 3/10 or 5 3/9
2) Which is bigger, 5.3 or 5.3333333333...
Obviously, you can tell that Screen B is just a LITTLE bit bigger than screen A. So the answer is D (The last one)