Bunuel wrote:
All zebras have stripes, and the most widespread subspecies has the best-defined stripes. The stripes must therefore be of importance to the species. Since among these grassland grazers the stripes can hardly function as camouflage, they must serve as some sort of signal for other zebras.
Which one of the following, if true, most strongly supports the conclusion regarding a signaling function?
(A) The subspecies of zebras with the best-defined strips is also characterized by exceptional size and vigor.
(B) In certain tall grasses zebras can be harder to spot than grazing animals with a coat of uniform color.
(C) A visual signal transmitted among the members of a species can consist of a temporary change of color perceptible to other members of the species.
(D) Zebras react much faster to moving shapes that have stripes than they do to moving shapes that are otherwise identical but lack stripes.
(E) Zebras have a richer repertoire of vocal signals than do similar species such as horses.
IMO-
The conclusion is
The stripes must therefore be of importance to the species(A) The subspecies of zebras with the best-defined strips is also characterized by exceptional size and vigor.
-- The exceptional have the best defined stripes , but of what importance to the species ?
--Out
(B) In certain tall grasses zebras can be harder to spot than grazing animals with a coat of uniform color.
-- Does not support the conclusion in any way.
--Out
(C) A visual signal transmitted among the members of a species can consist of a temporary change of color perceptible to other members of the species.
--- Don't think we are dealing with change of color .
--- Out
(D) Zebras react much faster to moving shapes that have stripes than they do to moving shapes that are otherwise identical but lack stripes.
--- Stripes do not function as camouflage ,
but they function as a signal for the whole species --- Should be the answer
(E) Zebras have a richer repertoire of vocal signals than do similar species such as horses.
--If they are , then this fact perhaps weakens the conclusion.
--Out
D for me !!