Hi,
Let me see if I can clear up some of the confusion. Regarding the question type, remember that an
assumption is a missing link between the premises (the facts) and the conclusion (what the author wants you to believe. An inference is what must be true if the conclusion is true. A conclusion is the synthesis of all the information given in the premises.There was no conclusion in the paragraph-- only a list of facts. That's why this is a conclusion question.
Now, the facts are simply that
1) there have been sales declines,
2) research and development has increased, and
3) advertising has stayed the same.
Basically, this kind of causal argument in which we know that factor x (research and development) and factor y (advertising) are NOT responsible for the decrease in sales. Thus, the conclusion is that some other factor (a competing industry) is the cause.
D is just too far-sweeping, too broad a conclusion to draw based on what is happening to one single company.
GMAX tip: In conclusion and inference questions, always be wary of drawing extreme conclusions/inferences from moderate premises.
Let me know if this was still confusing--
Sarai
(For more tips and tricks regarding Conclusion questions, checkout the Critical Reasoning I video at gmaxonline!)