Item 2
Read the excerpt from "Marie Curie and the Discovery of Radioactivity."

It was a thrilling time to be a scientist. The year the Curies were married, 1895, a German physicist named Wilhelm Roentgen discovered a new kind of ray that could be used to “see” inside people and photograph their bones. He called them X rays. The X stood for “unknown.”

Not long after, the French physicist Henri Becquerel discovered that uranium let out another type of ray. These rays were weak compared to X rays, and even Becquerel himself did not think his discovery of much importance. But Marie found the rays fascinating. Where did they come from? How were they produced? She decided to examine these mysterious “Becquerel rays” for her advanced research.

What is the author’s purpose in mentioning Wilhelm Roentgen and Henri Becquerel in "Marie Curie and the Discovery of Radioactivity"?

to describe important mentors for Curie

to explain who inspired Curie to study rays

to describe the difference between uranium and radium

to explain the difference between an X ray and a Becquerel ray