Damn, for some reason I just assumed that correct answer choices would always support the main conclusion. Never realized right AC could be supporting sub-conclusions.

Ellen Cassidy?? lol

If you are pretty sure you could get a 174+ then I say do it. Pretty sure that will begin to open to the doors into higher ranked T1 schools, granted it is still no guarantee that you'll get into them. At the end of the day, if a 172 got you to your ultimate goal, then be content with it.