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 how does the last sentence elaborate on the passage’s key event? a it suggests what infrasounds are used for. b it highlights what the scientists first heard. c it demonstrates that infrasounds cannot be heard by people. d it explains why elephants use senses other than smell and touch.

Explanation:

The passage is about elephants' communication, and the last - sentence "These sounds, known as 'infrasounds,' can travel several miles. It is thought they are a" suggests the possible use of infrasounds for elephants' communication.

Answer:

A. It suggests what infrasounds are used for.