patto
Hi!
I have a doubt about this question. I directly cross out the answer choices using present perfect tense. My reasoning is that the prices of the previous months fell, they are not still falling... (which present perfect seems to suggest). Then, why is present perfect correct?
You ask a great question, and one thing that has to be mentioned here is that, in GMAT Sentence Correction questions, the correct answers often involve structures or tenses used in less commonly known ways, so that people don't easily see that the correct answers are correct.
So, for instance, since Sentence Correction question writers are aware that it is commonly known that the present perfect tense is used in sentences meant to convey that events continue to go on in the present, the writers may choose to use the present perfect in a sentence in about events that don't necessarily seem to continue to go on in the present to confuse test takers.
Why can they do so? Because, actually, there are other less commonly known ways in which the present perfect tense can be used.
Among these ways are:
- To express that events occurred multiple times in the past and may occur again. Example: I have gone to Spain many times.
- In expressing that an event occurred very recently. Example: She has just arrived.
- In talking about an event that occurred in the past but in a way that emphasizes that the event is affecting the present. Example: It has been discovered that sugar consumption is associated with various health issues.
So, in choice (A), the use of the present perfect makes sense in that one could make the case that the prices have fallen and will continue to fall, that the prices have fallen on multiple occasions and may continue to fall, or that the sentence is meant to emphasize that the falling of the prices is affecting the present.
Overall, the takeaway here is that using choice of tense as a decision point for eliminating choices is not always optimal. For instance, in this case, one could make a case for using the simple past or for using the past perfect. So, you have to be careful when using tense choice as a decision point, and if you do use choice of tense as a decision point, you may want to confirm your choice by looking for other issues in the choices.
In this question, choices (B), (C), (D), and (E) all include issues other than tense that you could use as reasons for eliminating those choices.