The electromagnetic waves described as both beneficial and detrimental to human health are waves.

The answer is X- rays. The benefit of X rays is their use in medical imaging. This is because of their property to penetrate some matter, such as tissues, differentially. This property is significant in disease diagnosis. However, X rays are detrimental to the human health, especially in above-recommended doses. The high energy of X rays can damage DNA in cells and cause mutations that lead to cancer.

answer; i believe that the correct answer is (a); a large rock being weathered by wind and rain;