Read these lines: "There are wealthy gentlemen in England who drive four-horse passenger-coaches twenty or thirty miles on a daily line, in the summer, because the privilege costs them considerable money; but if they were offered wages for the service, that would turn it into work and then they would resign." The example of the wealthy drivers supports the claim that

1. The men drive the same route, the same distance, on the same days, in both halves of the example. 2. In the first half they pay for the privilege, and they keep doing it. 3. In the second half they are offered wages, and they resign. 4. Since the act itself never changes, the change must lie in whether it is owed to someone. 5. That is option C. 6. Option D would need low pay to be the trouble, but any wage at all is said to spoil it. 7. Option B mistakes the cost for the point, when the cost is only what keeps the act voluntary. _Source: Mark Twain, The Adventures of Tom Sawyer (1876), public domain_