Fish currently costs about the same at seafood stores throughout Eastville and its surrounding suburbs. Seafood stores buy fish from the same wholesalers and at the same prices, and other business expenses have also been about the same. But new tax breaks will substantially lower the cost of doing business within the city. Therefore, in the future, profit margins will be higher at seafood stores within the city than at suburban seafood stores.

For the purposes of evaluating the argument, it would be most useful to know whether

(A) More fish wholesalers are located within the city than in the surrounding suburbs
(B) Any people who currently own seafood stores in the suburbs surrounding Eastville will relocate their businesses nearer to the city
(C) The wholesale price of fish is likely to fall in the future
(D) Fish has always cost about the same at seafood stores throughout Eastville and its surrounding suburbs
(E) Seafood stores within the city will in the future set prices that are lower than those at suburban seafood stores

OA:E
I understand how E is important.
But how do we rule out B answer choice ?
In fact I find E as an extension to B.
B says that Any people who currently own seafood stores in the suburbs surrounding Eastville will relocate their businesses nearer to the city.
Thus, if that happens, the greater number of shops would lead to lessening of the prices and that would in turn lead to reduced profits as expected.
If that does not happen, then there will be increase in profit as expected.

Hence, I feel that B is also affecting the conclusion in both ways as E does.
How to make the choice between B and E then ?
Any help please.