aditya8062 wrote:Members of the Amazonian Akabe people commonly take an early-morning drink of a tea made from the leaves of a forest plant. Although they greatly enjoy this drink, at dawn they drink it only in small amounts. Anthropologists hypothesize that since this tea is extraordinarily high in caffeine, the explanation for the Akabe's not drinking more of it at dawn is that high caffeine intake would destroy the surefootedness that their daily tasks require

Which one of the following, if true, most seriously calls the anthropologists' explanation into question?
(A) The drink is full of nutrients otherwise absent from the Akabe diet.
(B) The Akabe also drink the tea in the evening, after their day's work is done.
(C) The leaves used for the tea contain a soluble narcotic.
(D) Akabe children are introduced to the tea in only a very weak form.
(E) When celebrating, the Akabe drink the tea in large quantities.

my concern: i am not able to understand as how any of the choices can be selected?

kutlee wrote:Thanks Mitch, Although option C looks good, from the argument it is clear that the tea contains 'extraordinarily high caffeine'. So how does it compare to 'subtle amount' of narcotic. So we have to assume that effects produced by 'high caffeine' are comparable to those by 'subtle narcotic'.

GMATGuruNY wrote:

aditya8062 wrote:Members of the Amazonian Akabe people commonly take an early-morning drink of a tea made from the leaves of a forest plant. Although they greatly enjoy this drink, at dawn they drink it only in small amounts. Anthropologists hypothesize that since this tea is extraordinarily high in caffeine, the explanation for the Akabe's not drinking more of it at dawn is that high caffeine intake would destroy the surefootedness that their daily tasks require

Which one of the following, if true, most seriously calls the anthropologists' explanation into question?
(A) The drink is full of nutrients otherwise absent from the Akabe diet.
(B) The Akabe also drink the tea in the evening, after their day's work is done.
(C) The leaves used for the tea contain a soluble narcotic.
(D) Akabe children are introduced to the tea in only a very weak form.
(E) When celebrating, the Akabe drink the tea in large quantities.

my concern: i am not able to understand as how any of the choices can be selected?

The argument concludes that only small amounts of the tea are drunk at dawn because the tea is high in caffeine, which could affect the Akabes' sure-footedness.

One way to weaken the conclusion is to suggest an ALTERNATE CAUSE.
C: The leaves used for the tea contain a soluble narcotic.
A SOLUBLE NARCOTIC could clearly affect the Akabes' sure-footedness.
If only small amounts of the tea are drunk at dawn because of the SOLUBLE NARCOTIC, then the argument cannot conclude that the high caffeine content is to blame.

The correct answer is C.

GMATGuruNY wrote:

aditya8062 wrote:Members of the Amazonian Akabe people commonly take an early-morning drink of a tea made from the leaves of a forest plant. Although they greatly enjoy this drink, at dawn they drink it only in small amounts. Anthropologists hypothesize that since this tea is extraordinarily high in caffeine, the explanation for the Akabe's not drinking more of it at dawn is that high caffeine intake would destroy the surefootedness that their daily tasks require

Which one of the following, if true, most seriously calls the anthropologists' explanation into question?
(A) The drink is full of nutrients otherwise absent from the Akabe diet.
(B) The Akabe also drink the tea in the evening, after their day's work is done.
(C) The leaves used for the tea contain a soluble narcotic.
(D) Akabe children are introduced to the tea in only a very weak form.
(E) When celebrating, the Akabe drink the tea in large quantities.

my concern: i am not able to understand as how any of the choices can be selected?

The argument concludes that only small amounts of the tea are drunk at dawn because the tea is high in caffeine, which could affect the Akabes' sure-footedness.

One way to weaken the conclusion is to suggest an ALTERNATE CAUSE.
C: The leaves used for the tea contain a soluble narcotic.
A SOLUBLE NARCOTIC could clearly affect the Akabes' sure-footedness.
If only small amounts of the tea are drunk at dawn because of the SOLUBLE NARCOTIC, then the argument cannot conclude that the high caffeine content is to blame.

The correct answer is C.