Ratio

Question
The question is asking for the ratio of flower to sugar (let's call Flower, F, and Sugar, S). So we need to find
F/S = ???

You seem to understand that I. is sufficient first, but let's see it:

I. Cups of flower is 250% of cups of sugar.
therefore ->
F = 2.5S
->
F/S = 2.5
We have the ratio and this is sufficient.

II. 1.5 more cups of flower than sugar.
This means:
F = S + 1.5 or F - S = 1.5

But you cannot separate F and S out to make a ratio (F/S). If you divided both sides by S, just to try, you would get:

F/S = (S+1.5)/S

which still means you don't have real numbers for your ratio.

therefore, we know that I. is sufficient and II is not, the answer is (A)

yes, the answer is A