Question

A trace element essential for plant growth and radioactive isotope which is used in cancer therapy is known as

• A. Cobalt
• B. Iron
• C. Calcium
• D. Sodium

Answer 1

The correct option is A Cobalt

• Cobalt is a trace element essential for plant growth and radioactive isotope which is used in cancer therapy.
• Cobalt in plant essential for nitrogen fixation in legumes and Cobalt-60 mostly used for radiotherapy cancer treatment.
  
• As there are other Essential trace elements include in plants are boron, chlorine, copper, iron, manganese, sodium, zinc, molybdenum, and nickel, silicon but they are not used in cancer therapy. so, option A cobalt is correct.