Cancer results when a mutation leads to which of the following?
cell death
apoptosis
loss of cell-cycle control
shutdown of the cell cycle

-Loss of cell-cycle control.

Explanation:

Cancer can be defined as a disease, characterized by tumor formation due to uncontrolled cell division. Cancer cells show loss of cell cycle control and inhibition of apoptosis (normal cell death).

Mutations that occur in cell division-controlling genes can arise cancer as these mutations cause loss of cell cycle control, due to which cells proliferate enormously without regulation and form tumors that later on develop into tumors.

Thus, the correct answer is 'third option.'