GRE General Test: RC-745617 GRE Reading Comprehension | TOEFL IELTS GMAT GRE SAT ACT PTE ESL

A certain type of shrimp habitually hovers around superheated deep-sea geysers, near which the bacteria that form the shrimps' diet can be found, Because the geysers emit a faint light, scientists have concluded that the shrimps' light sensitive dorsal patches were developed to locate the geysers and thereby find food.

Which of the following, if true, casts the most doubt on the scientists conclusion?

A The light to which the shrimps are sensitive is not the sort of light that the geysers emit

B The light given off by the geysers too faint to be detected by the human eye.

C The heat inside a geyser"s stream is sufficient to kill instantly any bacteria that move into it.

D Most other types of shrimp use eyes located at the end of eyestalks in order to see.

E In other types of shrimp, a heat-seasing organ has developed that could serve the same geyser-detecting purposes as the light sensitive patches are said to serve.