Question

read the passage. then answer the question. elephants communicate through sound elephants are very social animals, and scientists have long understood that they communicate with each other through smell and touch. however, there may be another way that elephants communicate: through sound. although scientists have studied various elephant sounds, they now believe elephants make very low frequency sounds that are too low for human ears to pick up. these sounds were first discovered when researchers noticed throbbing sensations in the air whenever elephants were together. special equipment revealed that they were making very low - pitched sounds. these sounds, known as “infrasounds,” can travel several miles. it is thought they are a which detail illustrates the idea that the throbbing sensations elephants made were actually sounds? a the sounds were able to travel for several miles. b elephants have various means of communication. c scientists believe that the sounds are a kind of language. d scientists used special equipment to identify the sounds

Explanation:

The passage mentions that special equipment was used to identify that the throbbing sensations were actually low - pitched sounds. This directly shows that the throbbing sensations were sounds. Options A, B, and C do not specifically address how the throbbing sensations were determined to be sounds.

Answer:

D. Scientists used special equipment to identify the sounds