Critical Reasoning

Cultural anthropologists who have been
observing and interviewing customers in retail
stores have announced a definitive theory of
consumer purchasing behavior.
Which of the following, if true, would be least
likely to represent a benefit of the theory to
retailers?
(A) Retailers will be able to eliminate costly
product displays that fail to increase
sales.
(B) Retailers will gain insight into how
consumers determine whether or not to
buy a particular product.
(C) The new theory will make consumers
aware of how product displays influence
their purchasing decisions.
(D) The new theory will determine what types
of retail display gimmicks produce a
negative reaction in consumers.
(E) The new theory will explain why consumers
often purchase at different stores goods
that could be bought at just one store.

OA: After some discussion, as I intend to see the reasoning going into this.

Experts need help to find the right approach to such questions. I can't find the precise cues to eliminate other answer choices and arrive at the answer. I could not arrive at the answer choice in multiple attempts.

Also, what is the level of difficult of this particular question?


Source is Kaplan Critical Reasoning Practice Sets: Set 2.