Nhận biết (M1)

Some researchers posit that the species inhabiting the South Pacific island of Grande Terre belong to clades that predate the island's split from remnants of the former supercontinent Gondwana around 80 million years ago. A study conducted by Michael A. Sundue et al. found, however, that the crown age (the age of the most recent common ancestor of all living and extinct species in the clade) of the clade of Grammitis ferns on Grande Terre is 8.5 million years; Sundue et al. further found that the crown age of the clade of Grammitis ferns in the South Pacific generally is approximately 10.0 million years.

Which choice best describes the overall structure of the text?

• A.

  It presents a possibility that some researchers have raised, then describes a study that clarifies their reasons for doing so.

• B.

  It explains a view some researchers have advanced, then discusses study results that led them to reconsider that view.

• C.

  It identifies a discrepancy between a hypothesis some researchers have proposed and related research findings, then explains that discrepancy.

• D.

  It describes an idea that some researchers have put forward, then presents study results that are incompatible with that idea.