Which describes the experiments of becquerel and the curies?

a. becquerel showed that uranium requires x-rays to form radiation, and the curies coined the term “radioactivity.”
b. becquerel coined the term “radioactivity,” and the curies showed that uranium requires x-rays to form radiation.
c. becquerel discovered other radioactive elements, and the curies showed that uranium gave off radioactivity.
d. becquerel showed that uranium gave off radioactivity, and the curies discovered other radioactive elements.