Infection with some types of HPV is the greatest risk factor for cervical cancer, followed by smoking. HIV infection is also a risk factor. Not all of the causes of cervical cancer are known, however, and several other contributing factors have been implicated.
https://en.wikipedia.org/wiki/Cervical_cancer
The following factors may raise a woman's risk of developing cervical cancer: Human papillomavirus (HPV) infection. The most important risk factor for cervical cancer is infection with HPV. Research shows that infection with this virus is a risk factor for cervical cancer. Sexual activity with someone who has HPV is the most common way someone gets HPV. There are different types of HPV, called strains. Immune system deficiency.
http://www.cancer.net/cancer-types/cervical-cancer/risk-factors
1 There are more than 100 types of HPV, 30-40 of which are sexually transmitted. 2  Of these, at least 15 are high-risk HPV strains that can cause cervical cancer. The others cause no symptoms or genital warts.  Up to 80 percent of women will contract HPV in their lifetime. Men get HPV, too, but there is no test for them.
http://www.cancercenter.com/cervical-cancer/risk-factors/
Cervical cancer is a cancer arising from the cervix. It is due to the abnormal growth of cells that have the ability to invade or spread to other parts of the body. Early on, typically no symptoms are seen. Later symptoms may include abnormal vaginal bleeding, pelvic pain, or pain during sexual intercourse.
https://en.wikipedia.org/wiki/Cervical_cancer
Cervical cancer cases linked to human papillomavirus (HPV) infection, UK. Cervical cancer cases linked to the use of oral contraceptives, UK. Cervical cancer cases linked to exposure to tobacco smoke, UK. 100% of cervical cases each year in the UK are linked to major lifestyle and other risk factors.[1] Cervical cancer risk is associated with a number of risk factors.[2,3] Cervical Cancer Risk Factors. Human papillomavirus (HPV) types 16,18, 31, 33, 35, 39, 45, 51, 52, 56, 58,59.
http://www.cancerresearchuk.org/health-professional/cancer-statistics/statistics-by-cancer-type/cervical-cancer/risk-factors
Human papillomavirus types 16 and 18 are the cause of 75% of cervical cancer cases globally, while 31 and 45 are the causes of another 10%. Women who have many sexual partners (or who have sex with men who have had many other partners) have a greater risk.
https://en.wikipedia.org/wiki/Cervical_cancer
Numerous environmental factors increase the risk of developing cancer. Tobacco smoke contains carcinogens that substantially increase the risk of developing cancers of the lungs, mouth, throat, esophagus, kidneys, and bladder. Pollutants in the air or water, such as asbestos, industrial waste, or cigarette smoke, can increase the cancer risk.
http://www.merckmanuals.com/home/cancer/overview-of-cancer/risk-factors-for-cancer
1 Of these, at least 15 are high-risk HPV strains that can cause cervical cancer. The others cause no symptoms or genital warts.  Up to 80 percent of women will contract HPV in their lifetime. Men get HPV, too, but there is no test for them.
http://www.cancercenter.com/cervical-cancer/risk-factors/
Cervical cancer risk factors. Infection of the cervix with human papillomavirus (HPV) is the most common cause of cervical cancer. However, not all women with an HPV infection will develop cervical cancer. Routine Pap testing is the best way to detect abnormal changes to the cervix before they develop into cancer.
http://www.cancercenter.com/cervical-cancer/risk-factors/
Other factors may be associated with cervical cancer risk because they increase the risk of Human papillomavirus (HPV) exposure or persistent HPV infection (and/or may have direct effects, independent of HPV).[1]
http://www.cancerresearchuk.org/health-professional/cancer-statistics/statistics-by-cancer-type/cervical-cancer/risk-factors
which of the following is the main risk factor for cervical cancer?
The main risk factor for cervical cancer is infection with human papillomavirus. The main risk factor for cervical cancer is infection with Human Papilloma Virus.