The right answer for the question that is being asked and shown above is that: "C. Using Credit." The <span>new concept that became popular with department stores is the use of credit cards. These credit cards are used instead of using cash.</span>
The discovery of radioactivity closely followed the discovery of X-Rays. The X-Ray was accidentally invented by Wilhelm Conrad Röntgen in 1895. With the help of his wife, Röntgen tested his wife's hand and captured the bones in her hand and her wedding ring. It became the first röntgenogram and garnered attention from the public and the scientific community.