Answer: (Detailed Solution Below)
Option D: Cobalt-60
Detailed Solution:
The correct answer is “Cobalt-60”.
Cobalt-60 is indeed used in the treatment of certain types of blood cancer, particularly as part of radiation therapy.
Cobalt-60 is a radioactive isotope that emits high-energy gamma rays. These gamma rays can be focused on cancerous cells to damage their DNA and inhibit their growth.