Question

Carcinogen present in cigarette smoke is:
A. Nitrosamine
B. Aflatoxin
C. Nicotine         
D. None of these

Answer 1

Hint: Cigarette smoke is a reactive, complex, and dynamic mixture that contains about five thousand chemicals, which possibly makes it the most significant source of toxic chemical exposure in people. 

Complete step-by-step answer:
A carcinogen is a chemical, organism, or agent capable of causing cancer. Carcinogens may take place naturally in the environment (like ultraviolet rays in sunlight as well as certain viruses) or may be produced by humans (like cigarette smoke and automobile exhaust fumes). Most carcinogens work through interaction with a cell’s DNA to generate mutations. Cigarette smoke carcinogens are contributing factors that synergize with human papillomavirus (HPV) to raise the risk of cervical cancer progression. Benzopyrene (BaP), a key carcinogen in cigarette smoke, is found in the cervical mucus and may act together with HPV.
Nitrosamine is a kind of chemical present in tobacco smoke and tobacco products. Nitrosamines are also present in several foods, which include beer, fish, meats, and fried foods. Some nitrosamines cause cancer in laboratory animals and may rise the risk of certain kinds of cancer in humans.
Aflatoxins are a family of toxins generated by certain fungi that are present on agricultural crops like peanuts, maize (corn), tree nuts, and cottonseed. The foremost fungi that generate aflatoxins are Aspergillus parasiticus and Aspergillus flavus, which are rich in warm and moist areas of the world.
Nicotine is the chemical in tobacco that keeps humans smoking. Nicotine reaches the brain in just a few seconds of taking a puff. In the brain, nicotine rises releases of brain chemicals known as neurotransmitters, which control behaviour and mood.

Therefore the correct answer is Option D.
Note: Lung cancer is still the most common cause of death in both women and men worldwide, killing more than one million persons every single year. Vast epidemiological data obviously links cigarette smoking with lung cancer, mostly because of the presence of cancer-causing chemicals known as carcinogens that are found in cigarette smoke.