Read the following statements (A - E) and answer the question following them.

A - Cancer and AIDS, both are incurable diseases.
B - Ionizing radiations like UV rays causes DNA damage and may cause cancer.
C - Cocaine is also known as crack.
D - Adolescence period is between 12-18 years of age.
E - CO (Carbon monoxide) content in the blood increases on smoking.

How many of the above statements are correct?

Only Statement B is incorrect.

Transformation of normal cells into cancerous neoplastic cells may be induced by physical, chemical or biological agents. These agents are called carcinogens. Ionising radiations like X-rays and gamma rays and non-ionizing radiations like UV cause DNA damage leading to neoplastic transformation. The chemical carcinogens present in tobacco smoke have been identified as a major cause of lung cancer. Cancer causing viruses called oncogenic viruses have genes called viral oncogenes. Furthermore, several genes called cellular oncogenes (c-onc) or proto oncogenes have been identified in normal cells which, when activated under certain conditions, could lead to oncogenic transformation of the cells.