Which Statement About Addiction and Genetics Is True

Which statement about addiction and genetics is true?

A) If both parents are alcoholics/drug addicts, their offspring will also be alcoholics/drug addicts, but if only one parent is affected, any offspring has a 50% chance of developing a problem.
B) An addiction gene has been identified.
C) The overall heritability of substance use disorders ranges from 40% to 60%.
D) If drug or alcohol problem does not run in a family, other family members will not develop a problem either.