Task: Question Answering
Input (English): Question: Jack and Jill are marathon runners. Jack can finish a marathon (42 km) in 5 hours and Jill can run a marathon in 4.2 hours.What is the ratio of their average running speed? (Jack: Jill)

 Option A: 14/15

 Option B: 15/14

 Option C: 4/5

 Option D: 21/25

 Option E: Cannot be determined
Output (English): Option D