I agree that "interactivity is correct." The text before the sentence in question sets up "Interactive shopping" as a key idea in the paragraph.

So I'm sorry to say that your teacher had the right answer, for the wrong reasons though. You can't eliminate response D simply by checking the subject-verb agreement. Instead, you need to look at the context of the sentence as it fits into the paragraph. The previous sentence explains that interactive shopping is going to have an effect. The next sentence then goes on to explain what that effect is.


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Most Subtle Official Straightman of the Laughing Hyenas -- Grammarian Brigade.

"The only medicine for suffering, crime, and all the other woes of mankind, is wisdom." -- Thomas Huxley

I don't care the answer is A
i have acccepted that
BUT
I do not agree that D is impossible
because i think it is a possible answer purely based upon grammar

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You know what I like about this after all is said and done?
We are ALL correct! From the more limited PoV, those who said "doesn't" were right in the context in which it was presented. From a more expanded PoV, even "don't" was correct. AND with the whole context revealed, the correct solution was able to be discerned.

I like it when we can all be "right"! http://www.ironworksforum.com/ubb/no...es/biggrin.gif

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"Allright! We'll call it a draw."

We just had some training at our school about standardized tests. The test creators intentionally create two answers that are very close. So if you find yourself narrowing the choices down to two and you can't figure out which one, you are doing exactly what the test creators hoped you would do.

In the case of this sentence, yes, public would be grammatically correct, but (and I'm sure you've heard this one before) it's not the "best" answer. The "best" answer would be A.


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Most Subtle Official Straightman of the Laughing Hyenas -- Grammarian Brigade.

"The only medicine for suffering, crime, and all the other woes of mankind, is wisdom." -- Thomas Huxley

I'm not sure. Was hoping you would have a clue http://www.ironworksforum.com/ubb/no...miles/wink.gif