Task: Question Answering
Input (English): Question: A certain quantity of 45% concentration solution is replaced with 15% concentration solution such that the concentration of the combined amount is 35%.
What's the ratio of the amount of solution that was replaced to the amount of solution that was not replaced?

 Option A: 1:3

 Option B: 1:2

 Option C: 2:3

 Option D: 2:1

 Option E: 3:1
Output (English): Option B