The Results of the Waterloo Smoking Prevention Project Suggest That

The results of the Waterloo smoking prevention project suggest that smoking prevention programs

A) are not very effective in the short-term.
B) are effective with older teenagers, but not younger teenagers.
C) are effective in the short-term but not in the long-term.
D) are most effective with young adults, ages 19-22.
E) are effective with younger teenagers, but not older teenagers.