Question

Which of the following can be inferred about the experiment described in the first paragraph?

• A. Researchers had difficulty verifying the existence of electroreceptors in the anteater because electroreceptors respond to such a narrow range of electrical field strengths.
• B. Researchers found that the level of nervous activity in the anteater’s brain increased dramatically as the strength of the electrical stimulus was increased.
• C. Researchers found that some areas of the anteater’s snout were not sensitive to a weak electrical stimulus
• D. Researchers tested small areas of the anteater’s snout in order to ensure that only electroreceptors were responding to the stimulus

Answer 1

The correct option is C Researchers found that some areas of the anteater’s snout were not sensitive to a weak electrical stimulus

The best answer is C. In the experiment described in the first passage, researchers described the electroreceptors in the anteater’s snout as “clustered” at the tip. Thus, it can be inferred that nervous activity was not recorded across the entire snout, but only in certain areas. Therefore, some areas of the snout, including those containing the tactile receptors, were not stimulated by the weak fields used in the experiment, as choice C suggests.
There is no information in the description of the experiment provided in the passage to suggest A, B or D.