Task: Question Answering
Input (English): Question: On a certain farm the ratio of horses to cows is 3:1. If the farm were to sell 15 horses and buy 15 cows, the ratio of horses to cows would then be 5:3. After the transaction, how many more horses than cows would the farm own?

 Option A: 20

 Option B: 30

 Option C: 40

 Option D: 50

 Option E: 60
Output (English): Option B