Barrett and Colleagues (2006) Found That Administering Nicotine (Through Tobacco

Barrett and colleagues (2006) found that administering nicotine (through tobacco smoke) leads most smokers to increase their alcohol consumption.According to the researchers, which of the following reasons may explain the cause?

A) Using both substances simultaneously may maximize the effects of both smoking and alcohol on the dopamine reward system.
B) Smoking becomes a conditioned stimulus for the alcohol and increases cravings for alcohol.
C) Alcohol maximizes the pleasurable effects of smoking on the dopamine reward system.
D) Nicotine may make drinking alcohol more rewarding in terms of its effect on the dopamine reward system.