Sentence Correction

Source : 800 Score

The Common Area is an agreement between Ireland, the UK and Commonwealth that citizens of these countries may travel within all of the countries without a passport, similar to the Nordic Union and the Sen Treaty.
A. The Common Area is an agreement between Ireland, the UK and Commonwealth that citizens of these countries may travel within all of the countries without a passport, similar to the Nordic Union and the Sen Treaty.
B. Similar to the Nordic Union and the Sen Treaty, the Common Area is an agreement between Ireland, the UK and the Commonwealth that citizens of these countries may travel within all of the countries without a passport.
C. The Common Area is similar to the Nordic Union and the Sen Treaty in that it is an agreement among Ireland, the UK and the Commonwealth that citizens of these countries may travel within all of the countries without a passport.
D. An agreement among Ireland, the UK and the Commonwealth that citizens of these countries may travel within all of the countries without a passport, the Common Area are similar to the Nordic Union and the Sen Treaty.
E. The Common Area is an agreement among Ireland, the UK and the Commonwealth that citizens of these countries may travel within all of the countries without a passport, similar to the Nordic Union and the Sen Treaty.

OA : C

Query:

""The Common Area is similar to the Nordic Union and the Sen Treaty in that it ""

I doubt this is the right answer !..
Will "IT" have a clear refernt ????[/spoiler]

Frustration first. OG 11th edition says "in that" is too formal to use it in GMAT land. but alas!!!(actually more like, ROAR!!)

Anyway, let's get down to business.

A and B are out because of "between". We need "among" (more than 2 countries..)

D. Agreement(subject)...may travel(verb)? Agreement can't travel right? so D is out.

E. modifier "similar to..." should be close to "the common area". The modifier is way too far way. So, E is out.

Therefore, C is the correct answer. I am not a big fan of "in that" phrase(at least when I study GMAT), but sometimes it is the answer by POE. I hope this does not happen in Real GMAT.

Hope this helps.