Task: Question Answering
Input (English): Question: A petrol pump owner mixed leaded and unleaded petrol in such a way that the mixture contains 10% unleaded petrol. What quantity of leaded petrol should be added to 1 ltr mixture so that the percentage of unleaded petrol becomes 5%?

 Option A: 1000 ml

 Option B: 900 ml

 Option C: 1900 ml

 Option D: 1800 ml

 Option E: None of these
Output (English): Option A