Task: Question Answering
Input (English): Question: In a small snack shop, the average (arithmetic mean) revenue was $400 per day over a 10-day period. During this period, if the average daily revenue was $360 for the first 6 days, what was the average daily revenue for the last 4 days?

 Option A: $420

 Option B: $440

 Option C: $450

 Option D: $460

 Option E: $480
Output (English): Option D