Nhận biết (M1)

Cuttlefish and toads see in three dimensions (3D) by combining two images in their brains, one from each eye. This produces a sense of depth, helping the animals judge how close or far away an object is. Researchers have investigated 3D vision in praying mantises as well. In one study, Vivek Nityananda and his team fitted mantises’ faces with two different color filters, one covering each eye, much like the filters in 3D glasses once worn at movies. By observing the mantises’ reaction to projected images, the team confirmed that mantises do indeed have 3D vision, but it’s unlike that of other animals.

Which choice best states the function of the underlined portion in the text as a whole?

• A.

  It identifies a potential problem that the researchers faced while studying the praying mantises.

• B.

  It offers a comparison meant to aid understanding of the praying mantis study.

• C.

  It emphasizes a difference between the research on praying mantis vision and research on other animals’ vision.

• D.

  It describes an earlier use of a tool the researchers used in the praying mantis study.