The state of Maine, in the extreme northeast corner of the c

After removing warmups and middle men the statement is essentially reduced to the following:

X shares land borders with 2 provinces, but only is adjacent with one state

Correct Idiom usage is adjacent to (sth). So we can cancel out A & B.
Comparisons in the sentence don't seem to be parallel; the correct version would maintain the parallel structure : X shares something But is doing something else too. "Only" breaks this parallel structure. D is out. We are left with C & E.
Another error is with the misplaced modifier only and it changes the meaning by modifying X and thus making it to look as if Its a bad thing for x to be adjacent with another state. It should modify "One" here.

[spoiler]The correct answer seems to be: C[/spoiler]

Thanks & Regards,
Vivek

{A} - INCORRECT; we need "other" adjective before "state"
{B} - INCORRECT; we need "other" adjective before "state"; only is needed to keep the uniqueness
{C} - CORRECT
{D} - INCORRECT; we need "other" adjective before "state"; "wrong placement of "only" verb "is" should have been there.
{E} - INCORRECT; "only adjacent" changes the meaning.... we need a limiter "only" for "other state".. as the use of "but" signifies..

i BELIEVE OA is B

Simply because the usage of "other one" seems awkward.C and E elininated

A ,D is wrong because "is only" should be used as "only is" is wrong usage.

---------------------------------------------------
“Good things come to those who wait… greater things come to those who get off their ass and do anything to make it happen.”