What evidence indicates that many people with drug addiction had a predisposition toward abuse?

a. Brothers and sisters of the person with drug addiction show similar abnormalities of brain and behavior.

b. People with drug addiction remember having a positive experience in their first encounter with the drug.

c. Most young people can accurately predict whether they will eventually develop a drug addiction.

d. An fMRI study on newborns accurately predicted which ones would later develop drug addiction.