This cannot be killed by apoptosis

The correct option is cancer cells.

Apoptosis, often referred to as programmed cell death, is a highly regulated and essential physiological process that multicellular organisms use to eliminate damaged, useless, or potentially dangerous cells. Under normal conditions, cells with significant DNA damage, cells infected with intracellular pathogens like viruses, and aging or activated immune cells that are no longer needed are signaled to undergo apoptosis to protect the integrity and health of the organism.

However, cancer cells are characterized by their ability to evade this programmed cell death mechanism. Due to specific genetic mutations (such as the loss of function in tumor suppressor genes like p53, or the overexpression of anti-apoptotic proteins like Bcl-2), cancer cells can bypass the signals that would normally trigger apoptosis. This resistance allows them to survive, replicate uncontrollably, and accumulate further mutations despite having severe DNA damage or abnormalities that would cause normal cells to self-destruct.