The table gives the number of employees in four firms operating in the same industry, the average number of hours worked per day, and the total output produced by each firm each day. Which firm has the most productive workers?
- A4 workers; 8 hours; 320 units
- B5 workers; 7 hours; 420 units
- C6 workers; 7 hours; 462 units
- D7 workers; 9 hours; 630 units