"From that time forth she lived in caves and among mountain cliffs. Her form faded with grief, till at last all her flesh shrank away. Her bones were changed into rocks and there was nothing left of her but her voice. With that she is still ready to reply to any one who calls her, and keeps up her old habit of having the last word."

The Ancient Greeks believed this explained what natural phenomenon?
A. a type of flower
B. an echo
C. a storm
D. the ability to speak