b. most of America's ex-smokers were able to kick the habit on their own
Research on addictive drugs most clearly indicates that
a.the medical use of morphine to control pain typically leads to addiction.
b.most of America's ex-smokers were able to kick the habit on their own.
c.addictions to narcotic drugs cannot be overcome without professional treatment programs.
d.those who occasionally use marijuana will almost always develop an addiction to this drug.