Question

Fill in the blank with the most suitable option:
It can be inferred from the passage that calcium carbonate shells ___________________.

• A. Are not as susceptible to deterioration as rocks
• B. Are less common in sediments formed during an ice age
• C. Are found only in areas that were once covered by land ice
• D. Contain radioactive material that can be used to determine a sediment's isotopic composition
• E. Reflect the isotopic composition of the water at the time the shells were formed

Answer 1

The correct option is E Reflect the isotopic composition of the water at the time the shells were formed

According to the fourth sentence of the third paragraph, the degree of enrichment of oxygen 18, which is one of the isotope, can be determined by analyzing ocean sediments of the period which are composed of calcium carbonate shells. This statement proves that E is the correct answer.

We cannot consider the other options as they are not supported by the passage.