Doubt in CR

gauravgundal wrote:The state legislature has proposed a new law that would provide a tax credit to people who install alarm system in their homes. Members of the legislature claim that the new law will reduce crime ,citing studies showing that crime rates fall as the percentage of homes with alarm system rises

Which of the following ,if true would cast the most doubt on the claim that the new law will reduce crime ?

B. The amount of the tax credit is so low relative to the cost of alarm systems that very few people will install alarm systems to obtain this credit

C. Neighborhood crime prevention programs can reduce crime as effectively as alarm systems can.

Source Kaplan

[spoiler]OA : B[/spoiler]

Why C is incorrect? We can predict from C that some other program has caused reduction in crime rates.
Expert please give us your valuable comments on this .

Members of the legislature claim that the new law will reduce crime
cast the most doubt on the claim that the new law will reduce crime ?

The prompt, as we see it, is not dealing with two simultaneous events. In fact, nothing has happened--they are predicting the future. The legislature predicts that they will reduce crime via this tax credit to encourage alarm systems. The correct answer, therefore, will somehow suggest that their plan will fail and the crime rate will not drop. If another thing might ALSO work, that tells us nothing about whether THIS plan will. (B) might bring into question the wisdom of acting on the legislature's prediction, but does not affect the legislatures accuracy--it is therefore not the right answer to this question.