I’d say the last one, the cancer cells lack inhibition and the do not stop reproducing. The rest of the answers don’t really make sense. The cancer cells can be controlled with chemotherapy so the first one is definitely wrong. And I do not believe that they contain stem cells. The last one is right because the reason cells become cancerous is because their growth inhibitors are broken or switched off, so they do not know when to stop growing and it becomes a problem for the body.
