How does radiation treat cancer?
a. it cools down the cancer cells and weakens them.
b. it cools down the non-cancerous cells and strengthens them.
c. it heats up the cancer cells and weakens them.
d. it heats up the non-cancerous cells and strengthens them.

The correct answer is (c). It heats up the cancer cells and weakens them.

Cancer is caused due to the uncontrolled growth of normal cells. When normal cells skips the pathway of cell cycle regulation then there is a uncontrolled growth of cells called as cancerous cells. One of the technique that is used to weaken these cells is radiation. It works by damaging the DNA of the cancerous cell by heat treatment. Radiation generates heat and weakens the cell. As a result of this the cells do not divide further.