Question

in general, what causes normal cells to become cancer cells?
cell cycle arrest
metastasis
loss of cell cycle control
loss of the ability to divide

Explanation:

Cancer cells are characterized by uncontrolled cell division. Cell cycle arrest (\(cell\ cycle\ arrest\)) would prevent cell division, not cause cancer. Metastasis (\(metastasis\)) is the spread of cancer cells, not the cause of normal cells becoming cancerous. Loss of the ability to divide (\(loss\ of\ the\ ability\ to\ divide\)) is the opposite of what cancer cells do - cancer cells divide excessively. Loss of cell cycle control (\(loss\ of\ cell\ cycle\ control\)) means cells no longer follow the normal regulatory mechanisms for division, leading to uncontrolled growth, which is a hallmark of cancer.

Answer:

loss of cell cycle control