The most highly addictive drug from the year 1970s in the US country which becomes a problem is Alcohol.
Option C is the correct answer.
Drug addiction is the situation where an individual totally becomes addicted to a drug or any kind of medicine.
Alcohol was one of the most heavily consumed drugs by US citizens from the year 1970. There was warfare being held about forty years back due to drug addiction requiring to serve longer sentencing in jail. This sentencing wasn't curbed the drug addiction but rather promotes the illicit use of alcohol by the US citizens.
Therefore, alcohol was a drug-addictive that become a problem in the year 1970 for the country of the US.
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