Sentence Correction

The KwakiutI recognized one social unit larger than the tribe-the confederacy, which was a cluster of loosely knit, informally related neighboring tribes who interacted with themselves more often than between other tribes.

A. tribes who interacted with themselves more often than between

B. tribes who interacted among each other more often than among

C. tribes who interacted with one another more often than with

D. tribes, interacting among each other more often than between

E. tribes, interacting among one another more often than with

i have following questions :
question 1 : is it true that when two or more than two adjectives describe the same noun then those adjectives can be separated by commas?
as has been done here :which was a cluster of loosely knit, informally related neighboring tribes
i very faintly remember having read this rule some where in RON's post but cannot find it now so plz kindly confirm this rule .

my second question : when 2 people are there is it rite to say : they interact with each other
however when more than 2 people are there then its wise to say : ....interact with one another

my third question : also if we want to use "among" for showing interaction then we sud be saying : they interact among themselves (reflexive pronoun)

instructors plz help
thanks and regards

aditya8062 wrote:The KwakiutI recognized one social unit larger than the tribe-the confederacy, which was a cluster of loosely knit, informally related neighboring tribes who interacted with themselves more often than between other tribes.

A. tribes who interacted with themselves more often than between

B. tribes who interacted among each other more often than among

C. tribes who interacted with one another more often than with

D. tribes, interacting among each other more often than between

E. tribes, interacting among one another more often than with

A: tribes who interacted BETWEEN other tribes
B: tribes who interacted AMONG each other
D: interacting AMONG each other
E: interacting AMONG one another

Interact between and interact among are both idiomatically incorrect.
The correct idiom is X INTERACTS WITH Y.
Eliminate A, B, D and E.

The correct answer is C.

As for your other questions:

The appropriateness of a comma between two adjectives is not tested on the GMAT, so don't worry about this issue.

I'd probably use each other to refer to two things and one another to refer to more than two.
But unless GMAC has indicated its preference in an official explanation -- at the moment, no OE comes to mind -- I would avoid using this split to eliminate answers.

A reflexive pronoun (itself, himself, etc.) is appropriate when the subject not only performs the action but also RECEIVES it.
John hit himself with a hammer.
Here, John not only performs the action (he HIT) but also receives the action (he WAS HIT by the hammer).
In the SC above, it is not possible for a tribe to interact with ITSELF.
Thus, the use of themselves is inappropriate.

Is "Who", a subjective case pronoun correctly placed for the tribes? I thought, otherwise, it should refer to Kwakiuti.
I chose option E. But again as Mitch said, interacting among is glaringly wrong..

Thanks, Sonali.

"who" is very much a subject case of pronoun but i think u missing a point
the initial clause (The KwakiutI recognized one social unit larger than the tribe-the confederacy) has already ended and then we have a "which" clause .this which clause has lot of description in terms of adjectives and then talks of "tribes" ,which again is described. so "who" is definitely referring to "tribes"

Is there no need of comma before who?? as who is modifying tribes.