Task: Question Answering
Input (English): Question: A man can row upstream at 8kmph and downstream at 13 kmph. The speed of the stream is

 Option A: 2.5 km/hr

 Option B: 4.2 km/hr

 Option C: 5 km/hr

 Option D: 10.5 km/hr

 Option E: None
Output (English): Option A