emcheeks
Hi
GMATNinja,
I have a question about choice B:
We want to prove that chicken is not immune to the virus that causes Ferber's syndrome. And what I thought is that maybe there are some other factors other than feed that cause the virus (note that the clause before the underline didn't specify what factor, so I thought another factor that cause the virus would makes sense here, like what B is saying).
Could you help me with this, please? I hope I make myself clear, but please let me know if any more explanation is needed. Thank you so much!
Let's take a look at the passage before we take a closer look at (B).
The passage tells us:
- Cattle are frequently infected with Ferber's syndrome
- Ferber's syndrome is transmitted to cattle through their feed
- Chickens grown for food are regularly given the same feed that infects cattle, BUT
- These chickens are rarely observed to have Ferber's syndrome.
We're then asked to complete the sentence that tells us that the information above does NOT tell us chickens are immune to Ferber's syndrome, since_________
We don't want to
prove that chickens are not immune to the virus -- we need something that explains why the syndrome is rarely observed in chickens if they are NOT immune to it.
(B) tells us:
Quote:
(B) Ferber's syndrome has been found in animals that have not been fed the type of feed liable to be contaminated with the virus that can cause the disease
Remember, we're trying to find an explanation for how the chickens can
eat the same contaminated feed as the cows, yet we do not see them suffering from Ferber's syndrome. Also, this explanation cannot be that the chickens are immune to Ferber's syndrome.
You're right that (B) does tell us that there is some other factor, other than the feed, that causes the virus in some animals. However, knowing this doesn't help us address the discrepancy given above.
Maybe lions can get Ferber's syndrome if they eat the wrong type of wildebeest -- this doesn't explain why chickens are NOT observed to have Ferber's syndrome despite eating contaminated feed.
Since (B) doesn't help us resolve the discrepancy, it cannot be the answer to this question.
Compare this to (D):
Quote:
(D) chickens and cattle take more than a year to show symptoms of Ferber's syndrome, and chickens commercially raised for meat, unlike cattle, are generally brought to market during the first year of life
Both (D) and the passage talks about
"chickens commercially raised for meat", so we can be sure we're talking about the same animals.
(D) then tells us Ferber's syndrome can take more than a year to be noticeable BUT these chickens are
"brought to market" in their first year of life. We cannot
observe Ferber's syndrome in these chickens because they do not live long enough to display symptoms.
(D) provides information that helps us address the discrepancy given in the passage, so (D) is the answer to this question.
I hope that helps!