Final answer:
Cancer cells do not perform apoptosis, which is programmed cell death.
Step-by-step explanation:
In cancer, cells lose their ability to control cell division, leading to uncontrolled growth. A key characteristic of cancer cells is that they do not undergo apoptosis, which is programmed cell death. Apoptosis is a normal process that allows the body to remove damaged or unwanted cells.
Therefore, the correct option is a. Apoptosis. Cancer cells do not perform apoptosis.