Although we don't know the actual numbers of juniors and seniors, we can just use the percents in their place. After all, maybe there are exactly 100 junior and seniors total. So the ratio of juniors to seniors must be 22/26. This reduces to 11/13. When comparing two fractions (or ratios) in a QC, you can just make sure they have a common denominator. So

11/13 4/5

Turns into

55/65 52/65

So A is the correct answer. Notice by the way, that we didn't actually need to do the denominators, since we were only comparing the numerators. So you can save a bit of time and effort if you skip that part.