Task: Question Answering
Input (English): Question: The banker's discount on Rs. 1600 at 15% per annum is the same as true discount on Rs. 1680 for the same time and at the same rate. What is the time?

 Option A: 3 months

 Option B: 4 months

 Option C: 5 months

 Option D: 6 months

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