Debashis Roy
(C) doesn't weaken the plan, but then neither does (B).
The village is overrun by poisonous snakes.
Mayor's Plan:
If we pay $10 for each dead snake that a villager brings in, the village will get rid of snakes.
Note that the mayor's plan is not to "announce" that $10 will be given. He is saying "pay $10". Whether villagers trust the mayor or not is irrelevant. If each villager who brings in a dead snake is given $10, trust on the mayor does not matter. The plan should be successful.
B) village taxes will triple if the mayor's proposal is implemented
Whether the plan will be successful or not depends on what happens after the plan is implemented.
Once the mayor has implemented the plan, the people can either catch snakes and get $10 making his plan successful or they can refuse to do so which leads to failure of his plan. If the taxes do increase, there is nothin that people can do. They might as well earn $10 for each snake and make up the lost money. It is unlikely that they will all decide to boycott the plan to bring the village back o original state.
If faced with this question, I will go for (C) but I don't like this question much.