Which has the least influence in whether a teen drinks alcohol?

The correct answer would be Police campaigns.

Explanation:

Alcohol is a colorless drink which is flammable, volatile and is highly intoxicated. It is made up of natural fermentation of sugar along with the Wine, beer, and other drink's intoxicating constituents. Consuming alcohol by people especially by teens is very dangerous, as it has a lot of health dangers associated with it. If a teenager starts to drink, his family attitudes, peer pressure and some awareness advertisements would have influence over his this attitude, but police campaigns about not to consume alcohol won't have a significant influence on a teenager.

Regular consumption of alcohol is very dangerous. It may cause the following diseases:

Liver failure

Kidney failure

Diabetes

Bladder and Prostate inflammation

Hepatitis

Jaundice, etc.

That is why, consuming alcohol is prohibited in some religions.