The citizens' group is faulting the mayor, not for his plan per se, but in his claim that he is trying to help the economy. If such were the case, then he would use the revenues in a project that best helps the economy. Because the mayor is not doing so, the citizens' group concludes that he must have another agenda. The basic principle: if you want to help the economy, you will choose the means that most effectively does so. Generalizing even more, we get answer (A): whatever your cause, you will always choose a course of action that best helps that cause.
As for why the other answer are wrong, see below:
Which one of the following principles, if accepted, would most help the citizens’ group to justify drawing its conclusion that the mayor has in mind interests other than Plainsville’s economy?(A) Anyone really pursuing a cause will choose the means that that person believes will advance the cause the farthest.
THE ANSWER(B) Any goal that includes helping the economy of a community will require public revenues in order to be achieved.
The citizens are more focused on how the governor is not taking the optimal path in helping the economy. The use of public revenues in specifically helping the economy is not at issue.(C) Anyone planning to use resources collected from a group must consult the members of the group before using the resources.
The Citizens' group is not faulting the governor for not consulting it. Instead, it is faulting the governor for not choosing a use of funds that would BEST help the economy. (D) Any cause worth committing oneself to must include specific goals toward which one can work.
This may be a tempting answer, because it is often true in real life. However, it has nothing to do with the argument.(E) Any cause not pursued by public officials, if it is to be pursued at all, must be pursued by members of the community.
This answer choice is not relevant to the Citizens' group's objection.
Hope that helps
Magoosh Test Prep