One Feifei C/R FeiFei-64--->beautywawa转移

If the city council institutes new parking regulations, city revenues will surely increase, since studies have conclusively shown that, if such parking regulations are put into effect, there is an increase in parking violations, and an increase in parking violations will result in a greater number of parking fines collected.

64. If the statements in the passage are true, which one of the following must also be true?

A.        Unless there is an increase in the number of parking violations in the city, city revenues will not increase.

B.        If the city council institutes new parking regulations, the council will fall from favor with the citizens.

C.        The city council will institute new parking regulations only if an increase in city revenues can be expected to result.

D.       If the city council’s new regulations cause more parking violators to be ticketed, the city revenues will increase.

E.        Unless the city institutes a complex system of parking regulations, the city cannot expect traffic violations to increase.

I did not choosed the best answer the first time when I worked on the above question.

Obviously, C is something re-written as per the passage. The purpose for the city council to institute the new parking regulations is to achieve more revenues. So the key, C looks true to me.  

D is the best key which I can understand after I refered to the given answers. My question is when we are working on the tens of C/R questions with limited time at a tight schedule, how can we get rid of the such misleading choices as C immediately?

I shall appreciate if you can give me some useful hints.

For LSAT questions, you have to pay attention to the nuance between choices, especially for "must be" question. May be one adjective or adverb word can rule out some choices. Like the quetion above, when  skimming the choice C and D, one will be confused with them. The nuance is that C says regulation surely causes revenues increase and that D points out more tickets render revenues to rise.Returning to passage, one can finds only regulations are put into effect, does the increase occurs. Instituting regulations itself must not cause revenues to go up

the first,when you see "only if" in the options, you should pay attention,because no such expression in the text,

fourthermore, 原文是措施达目的, 但并没说为了这个目的,才采取措施.

如原文改成 in order to increase city revenues,c 才有可能是正确的, 但仍要注意only if 的表达太绝对了

Thank you all for the valuable info. I think I get a lot more understanding on the questions of this type now.

不同意ztlbox有关only if的说法.

1. only if 是必要条件指示词, C错在充分必要条件互换了. in order to是充分条件指示词, 故对.

2. "only if 的表达太绝对了", 这个表达也太绝对了. 大家要客观判断选项的对与错, OG178就有only if为正确答案的.

3. 这道题也不是什么措施目的型. 而仅仅是充分必要条件推理.

个人理解, 大家讨论!