GMAT Sentence Correction (SC) | Re: The increasing costs of both materials and labor

1. Costs are plural and hence we can drop B and E.
2. Among A, C, and D, we must take that the increasing costs are an already begun phenomenon and that the downward trend is also a concurrent feature. Therefore, denoting the downward trend in futuristic terms is faulty. We can eliminate A and D on this count. C is the best among the choices.

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