Question #N549

The author of the following text discusses a group of animals’ adaptation to a challenging environment. The text also highlights the fact that humans are not always the cause of such adaptations. Many scientists have long believed that giraffes are mostly silent and communicate only visually with one another. But biologist Angela Stöger and her team analyzed hundreds of hours of recordings of giraffes in three European zoos and found that giraffes make a very low-pitched humming sound. The researchers claim that the giraffes use these sounds to communicate when it’s not possible for them to signal one another visually. This finding, they say, could help to explain why giraffes have such a low-pitched humming sound, which the team claims is used by giraffes in three European zoos, and that giraffes may not be as silent as they are often thought.

Which of the following inferences is BEST supported by the passage?
A. Giraffes are not as silent as scientists once thought.
B. The low-pitched humming sound used by giraffes in European zoos is a result of the giraffes’ adaptation to their environment.
C. The study by Stöger and her team conclusively proves that giraffes do not always communicate visually.
D. Giraffes in the wild are not as silent as giraffes in European zoos.

Correct Answer is: B

The text states that the researchers believe giraffes use the humming sound when visual communication is impossible. This implies that the low-pitched humming sound is an adaptation made by the giraffes to their environment. The passage does not provide information to support the other choices.