The Text Examples of American GIs Who Used Heroin During

The text examples of American GIs who used heroin during their service in the Vietnam War and countries such as France where people drink alcohol on a regularly basis all suggest that

A) exposure is a critical factor in addiction and people's ability to resist temptation.
B) drugs of all kinds are powerfully addictive and need government control to avoid widespread abuse.
C) self-control may have less to do with the power of the temptation and more to do with cultural beliefs about how much control a person should or can exercise.
D) self-control failure and success is heavily dependent on individual "will power" and not much affected by cultural and social factors.