The Development of the Linear Accelerator in the 1960s Was

The development of the linear accelerator in the 1960s was a breakthrough for the field of radiation oncology because it _____.

A) Afforded the opportunity to treat tumors deeply seated within the body
B) Allowed treatment of superficial tumors such as those on the skin or chest wall
C) Posed no occupational exposure risk for radiation therapists
D) Produced lower-energy x-rays than earlier methods