In malaria-infested areas, many children tend to suffer several bouts

In malaria-infested areas, many children tend to suffer several bouts of malaria before becoming immune to the disease. Clearly, what must be happening is that those childrenтАЩs immune systems are only weakly stimulated by a any single exposure to the malarial parasite and need to be challenged several times to produce an effective immune response.

Which of the following, if true, most seriously undermines the explanatory hypothesis?

PRETHINKING........IT IS NOT THAT AFTER SEVERAL BOUTS OF SIMILAR MALARIA, DOES ONE BECOME IMMUNE..... INFACT ONE COULS BECOME IMMUNE TO A SINGLE BOUT ALSO... BUT THE IMMUNITY DEVELOPED IS OF NO USE IN ANOTHER STAIN......


MATCHES "E"... HENCE IMO "E".....

a.Immediately after a child has suffered a bout of malaria, the childтАЩs caregivers tend to go to great lengths in taking precautions to prevent another infection, but this level of attention is not sustained............... IRRELEVANT...............
b.Malaria is spread from person to person by mosquitoes, and mosquitoes have become increasingly resistant to the pesticides used to control them. ......IRRELEVANT.............
c. A certain gene, if inherited by children from only one of their parents, can render those children largely immune to infection with malaria...IRRELEVANT.....
d.Antimalaria vaccines, of which several are in development, are all designed to work by stimulating the bodyтАЩs immune system.....SO WHAT... WE ARE TALKING OF SELF BUILT IMMUNITY.....
e. There are several distinct strains of malaria, and the bodyтАЩs immune response to any one of them does not protect it against the others......CORRECT....

ChiranjeevSingh

Choice C :- It tells that children are already immune to Malaria while argument talks about conditions post to infection. Am I positing right or there is another reasoning to knock down this option.

Yes. It says that some children can be already immune to malaria at their birth. However, the argument is concerned about "many" children who are not immune at birth.

- CJ

IMO is E

Reason being:
Since one strain of attack does not provide immunity against other type, it can
be noted that all the strains of malaria are experience and individual immunity is gained once for all.
So the body builds resistance against all the strains of malaria and is immune after exposure to few attacks.

Between C & E

C. children without this gene need to continue this process to produce effective immune response.
so this choice partially weakens and strengthens. can be eliminate choice C

E. is the winner

Anyone plz correct me if i am wrong with my reasoning
Single exposure-immune not developed
Multiple exposure-immune developed
To weaken it ,even multiple exposure will not develop it.
So there must be several strains which when exposed doesn't develop our immune system.
Here i am assuming that one strain exposed multiple times will develop the immune system.
Correct me if i am wrong.

Posted from my mobile device

the key to question is :
In malaria-infested areas, many children tend to suffer several bouts of malaria before becoming immune to the disease. Clearly, what must be happening is that those childrenт's immune systems are only weakly stimulated by a any single exposure to the malarial parasite and need to be challenged several times to produce an effective immune response.

Which of the following, if true, most seriously undermines the explanatory hypothesis?


A. Immediately after a child has suffered a bout of malaria, the child's caregivers tend to go to great lengths in taking precautions to prevent another infection, but this level of attention is not sustained.

B. Malaria is spread from person to person by mosquitoes, and mosquitoes have become increasingly resistant to the pesticides used to control them.

C. A certain gene, if inherited by children from only one of their parents, can render those children largely immune to infection with malaria.

D. Antimalaria vaccines, of which several are in development, are all designed to work by stimulating the bodyт's immune system.

E. There are several distinct strains of malaria, and the bodyт's immune response to any one of them does not protect it against the others.

E explains that whatever explains in argument won't work if true as mentioned in E

GMATNinja VeritasKarishma egmat MartyTargetTestPrep VeritasPrepBrian ChrisLele GMATGuruNY KyleWiddison CrackVerbalGMAT DmitryFarber VeritasPrepHailey
I have a problem with pre-thinking.
I don't know what I should keep in mind before going through each choice.
Could you please help elaborate on what I should pre-think or keep in my mind before looking at each choice?
Also, could you please provide explanations why either option C or D is not a correct answer?

I have two words for you.

Don't prethink.

You can keep in mind the elements of the argument in the passage and any analysis of the argument you have done, but there is absolutely no reason to prethink answers.

For more on this topic, see this video. https://www.youtube.com/watch?v=F16VCFxF_t4

The argument says that immune systems are weakly stimulated and must be challenged multiple times to produce an effective immune response. What if the immune system is highly stimulated, but the malaria strain is different each time?
The scope of the argument is limited to finding any new information that'll weaken the hypothesis - that immune systems are weakly stimulated and must be challenged multiple times to produce an effective immune response.

Option Elimination -

A. Immediately after a child has suffered a bout of malaria, the child's caregivers tend to go to great lengths in taking precautions to prevent another infection, but this level of attention is not sustained. - precautions taken are out of scope.

B. Malaria is spread from person to person by mosquitoes, and mosquitoes have become increasingly resistant to the pesticides used to control them. - Doesn't even talk about Children, immune system - out of scope.

C. A certain gene, if inherited by children from only one of their parents, can render those children largely immune to infection with malaria. - We are talking about the children who don't have this gene. Out of scope.

D. Antimalaria vaccines, of which several are in development, are all designed to work by stimulating the body's immune system. - vaccines are out of scope.

E. There are several distinct strains of malaria, and the body's immune response to any one of them does not protect it against the others. In line with our rethinking

GMATNinja What is wrong with Choice (A) here? Could it not be that if the caregivers' level of attention is not sustained, then the children can become more susceptible to malaria because of inconsistencies with the level of care that they are receiving? I thought this would provide an alternative explanation for why it's not the stimulation of the immune system that is responsible for children experiencing several attacks before they become immune. Tough call between (A) and (E) for me, but would love a breakdown of Choice (A) to understand why it's wrong.

I think option E is correct only if we assume that a person will get multiple exposure of same strain of malaria.

If in multiple exposure, the strains are different then the individual's immune is getting stronger against different malarial strains which actually supports the explanation : multiple exposure -> better immune response.

Let me know if this reasoning is correct.

Posted from my mobile device

­We're trying to explain why "many children tend to suffer SEVERAL bouts of malaria before becoming immune to the disease". Choice (A) might explain why some children are able to AVOID multiple bouts of malaria, but it doesn't explain why the children who DO suffer multiple bouts (regardless of care received) did not become immune after the first bout.

Choice (E) hits that nail on the head. If there are, say, five different strains, a child might suffer from all five before becoming completely immune to malaria.

I hope that helps!­