Lets deconstruct the argument
Background info / Premise : There are theories which are more successful at predicting human behavior, because they posit different casual mechanisms as compared to smith theory
Conclusion : Smith theory (no matter how elegant & complex they are) ought to be abandoned in favor of the other theories
Now we can go by two ways finding the gap between premise and conclusion or by negation (am going by negation)
A)
The Smith theory has not led to intriguing predictions, which have been shown to be false, about the causes of human behavior. (Supports the conclusion)B) A psychological theory with lesser predictive success than another is scientifically preferable (weakens the conclusion)C) The Smith theory has had less remarkable success in predicting how people will behave in certain situations (supports the conclusion)D) Measuring the predictive success of a psychological theory never involves considering other theories that attempt to explain the same phenomena (it goes against the premise and remember we can never challenge a premise)E) Scientific theories become practical if they posit causal mechanisms beyond a certain level of complexity.(Beyond certain limit is the not the point of contention)GMATNinja bb your comments on my reasoning