Individuals Who Have Alcohol Problems Tend to Come from Families

Individuals who have alcohol problems tend to come from families with other individuals who have alcohol problems. This would suggest that ________

A) genetic factors cause an individual to have alcohol problems.
B) environmental factors cause an individual to have alcohol problems.
C) both genetic and environmental factors cause an individual to have problems.
D) although there is an association, no cause-effect relationship can be concluded.