Question

rays have been in the oceans for a very long time. there are people who study rays. these people think rays lived 150 million years ago. the people who study rays think that rays a help keep oceans clean. b can make different sounds. c are a danger to people. d lived 150 million years ago.

Explanation:

The text clearly states "These people think rays lived 150 million years ago."

Answer:

D. lived 150 million years ago