Question

in the early 1950s, the geological community largely adhered to fixism, the belief that continents are permanently anchored and the ocean floor is geologically inert. this consensus was challenged when cartographer marie tharp, analyzing sonar profiles at columbia university, identified a continuous rift valley running along the mid - atlantic ridge. although her colleague bruce heezen initially dismissed the rift as an error, the subsequent discovery that the valley aligned perfectly with a map of earthquake epicenters compelled him to embrace the concept of a spreading seafloor. this synthesis of data eventually became a cornerstone for the developing theory of plate tectonics.
6 mark for review
which choice best describes the function of the underlined sentence in the text as a whole?
a it illustrates how corroborating evidence prompted a researcher to validate the prevailing theoretical framework described in the first sentence.
b it explains the technical methodology used to collect the sonar profiles mentioned in the previous sentence.
c it argues that the personal prejudices of a scientist delayed the acceptance of the discovery mentioned in the final sentence.
d it shows how additional data convinced a skeptical colleague to abandon the prevailing view.

Explanation:

• Option A: The first sentence's "fixism" is the prevailing framework, but the underlined sentence shows a shift from it, not validation. Eliminate.
• Option B: The underlined sentence is about a colleague's change of view, not about collecting sonar profiles. Eliminate.
• Option C: The underlined sentence focuses on the colleague accepting the discovery, not on delay due to prejudice. Eliminate.
• Option D: The underlined sentence says Heezen initially dismissed the rift, but the alignment with earthquake epicenters (additional data) made him embrace the spreading seafloor (abandon the prevailing fixism view). This matches.

Answer:

D. It shows how additional data convinced a skeptical colleague to abandon the prevailing view.