Task: Question Answering
Input (English): Question: If a boat is rowed downstream for 600 km in 20 hours and upstream for 48 km in 4 hours, what is the speed of the boat and the river?

 Option A: 21 , 21

 Option B: 9 , 21

 Option C: 21 , 9

 Option D: 9 , 9

 Option E: 20 , 8
Output (English): Option C