Match the following columns.

	Column I (Cancer-causing agents)		Column II (Examples)
A.	Chemical agent	(i)	Benzopyrene in cigarette smoke
B.	Physical agent	(ii)	X-rays
C.	Biological agent	(iii)	Oncogenic viruses

	A	B	C
1.	i	ii	iii
2.	iii	ii	i
3.	iii	i	ii
4.	i	iii	ii

UV rays from sunshine, ionising radiation from X-rays, radioactive elements in industry, and the general environment are examples of physical carcinogens.

Chemical carcinogens include industrial effluents, pollutants from automobiles, homes, and factories, as well as harmful chemicals in cigarette smoke. Acrylamide and Benzopyrene in cigarette smoke are two examples. 

Oncogenic viruses are biological carcinogens (cancer-causing viruses). Human papillomavirus, Epstein-Barr virus, and hepatitis B virus are only a few examples of viruses with DNA genomes.