The logical appeal against increasing the time of the school day for more standardized test preparation is Extending the time of the school day clearly will cost a lot of money.
Explanation:
The objective is to appeal against to increasing the time and only one of the options is actually going in that direction, saying that extending the school day will affect the economic budget is a clear and very direct form to convince others to vote against the idea, the other options refer to changes inside the same hours program or the obligation of school preparing the students.
When you see a sentence not make sense it's usually because you are leaving out important words or mixing them up in the wrong way in that sentence so due to this knowledge a dangling modifier would be C.