A patient tells the nurse that he read that asbestos is a carcinogen and asks whether that means it causes cancer. Which of the following explains what a carcinogen is?
a) Any agent or condition that can promote the proliferation of altered, mutated cells
b) Any chemical, physical, or genetic agent that can irreversibly alter cellular DNA, causing abnormal cells to be produced
c) Any agent or condition that causes chronic irritation and stimulation of tissue, resulting in uncontrolled overgrowth of tissue
d) A specific, known chemical or physical agent that can start uncontrolled cellular proliferation by fracturing cellular DNA