In General, Work on the Effectiveness of Antidrug, Antidrinking, and Antismoking

In general, work on the effectiveness of antidrug, antidrinking, and antismoking ads indicates that

A) these ads are not effective because the power of other pressures to drink, smoke, and use drugs is so strong.
B) the only people who are persuaded by the ads are those who would not drink, smoke, or use drugs anyway.
C) attitudes are affected but behavior is not.
D) attitudes are affected and behavior is too, but by a lesser amount.