Task: Question Answering
Input (English): Question: A crow leaves its nest, and flies back and forth from its nest to a nearby ditch to gather worms. The distance between the nest and the ditch is 250 meters. In one and a half hours, the crow manages to bring worms to its nest 15 times. What is the speed of the crow in kilometers per hour?

 Option A: 1

 Option B: 3

 Option C: 4

 Option D: 5

 Option E: 6
Output (English): Option D