Data collected from the Biological Effects of Ionizing Radiation (BEIR) VII, Phase 2 study indicate that approximately ______ diagnostic medical examinations and ________ dental x-ray examinations are performed annually in the United States.
a. 300 million, 100 million
b. 400 million, 150 million
c. 500 million, 200 million
d. 600 million, 250 million