Samakshkapoor92 wrote:
guys,
can one of you explain why b is not the best choice, cant wrap the fact around my head that since c clearly shows that the data collected would be wrong or incomplete.
Samakshkapoor92, when you answer a CR question (or an RC question, for that matter), your task is to find which answer choice is correct based on the
passage,
not on information that is contained in the other answer choices. Essentially, you should treat each answer choice as if it exists in a vacuum with only the text of the passage, and make your decisions one by one. So let's go through the options that are giving you trouble:
Quote:
B. Thomasville has reliable records to show which trees in existence 20 years ago were cut down to permit new construction downtown.
Remember, we are looking for a statement that "most seriously undermines the claim that the tree planting proposal will assure an abundant tree population." The proposal relies on data from 20 years ago and current data to determine which trees will most likely survive another 20 years. Answer choice (B) introduces a wrinkle in the data, which is that some of the trees that did not survive "were cut down to permit new construction." This, on the surface, sounds like it will create a problem for the proposal.
However, the answer choice doesn't merely state that some trees were cut down due to construction. It specifies that Thomasville
has reliable records about exactly which trees were cut down. Can the fact that Thomasville has reliable records of this data undermine the proposal? Definitely not -- having reliable records could only help fix the complication that is introduced by the answer choice. You can eliminate (B) for this reason.
Quote:
C. A number of trees from one of the species widespread in Thomasville 20 years ago reached the end of their natural life span in the intervening period.
The goal of the "proposal" is to "assure downtown Thomasville of an abundant tree population 20 years from now." This answer choice tells us that a number of one particular species of tree died off naturally within the past twenty years. Is this because that kind of tree generally lives less than twenty years? Or because the trees were all planted at the same time more than twenty years ago? The first option would strengthen the proposal, while the second would call the data into question. We are not given enough information to determine the reason behind this statement, and therefore its effect on the strength of the proposal.
What we
do know is that other types of trees
have survived for the past twenty years, and that the proposal advocates planting those trees. So, answer choice (C) does not significantly undermine the proposal and we can throw it out.
Finally, take a look at the correct answer:
Quote:
E. A city with a high proportion of an any one species of the trees can have its tree Population devastated by one outbreak of a disease.
The proposal advocates planting trees "primarily from
the species that turns out to have the best record of survival." Because one species will be planted more than the others, this answer choice significantly undermines the proposal. If the tree population can be devastated by one outbreak of a disease, then it is likely that Thomasville will not have an abundance of trees in twenty years if the town adopts the proposal.
Answer (E) is correct.
I hope this helps!
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