Which statement about cancer is true? A) Cancer starts when cells stop growing and dividing. B) Growth factors control when and how fast cells die. C) Mutations in certain genes cause tumors.

C should be correct.

A is incorrect because cancer is when cells reproduce too quickly and out of control.

B is incorrect because growth factors control the reproduction of cells, not when they die.

I'm honestly not sure about the last one, but it's the only one left.