Task: Question Answering
Input (English): Question: A truck driver drove for 2 days. On the second day, he drove 3 hours longer and at an average speed of 15 miles per hour faster than he drove on the first day. If he drove a total of 1,020 miles and spent 21 hours driving during the 2 days, what was his average speed on the first day, in miles per hour?

 Option A: 25

 Option B: 30

 Option C: 35

 Option D: 40

 Option E: 45
Output (English): Option D