Which statement is an example of "philosophic doubt"?
A . Attention is the most powerful reinforcer for most clients so it will probably work with Freddie.
B . I have many reservations about using the principles of behavior in designing treatment programs.
C . I really do not think that food functions as a reinforcer for Linda since she often misses meals.
D . Past research has shown that verbal behavior training is effective but this could change when new research is conducted.
Answer: D