4. which of the following is not used by scientists on earth to observe x - rays and gamma rays? satellites…

Brief Explanations:

X - rays and gamma - rays are mostly absorbed by Earth's atmosphere. Satellites, scientific balloons, and rocket flights can take instruments above most of the atmosphere to observe them. Telescopes on Mount Everest are still within the atmosphere and cannot effectively observe x - rays and gamma - rays due to atmospheric absorption.

Answer:

C. telescopes on Mount Everest