In Applied Behavior Analysis a response class is defined as a group of responses that either share a common form topography or more commonly have the same function ie they produce the same outcome or are evoked by the same discriminative stimuli In this scenario the handshake smile and fist bump all serve the identical functiongreeting students and acknowledging their arrivaland are reliably evoked by the same antecedent students entering the classroom Despite their differing topographies how they look physically their shared function places them within the same response class Understanding response classes is crucial because interventions targeting one member of a class may generalize to other members or conversely multiple topographies may need to be taught to achieve the desired functional outcome Option A is incorrect because a reinforcer is a consequence that increases the future probability of a behavior not the behavior itself Option B describes a stimulus class which is a group of stimuli that share a common element eg formal similarity temporal locus or function and evoke the same response or set of responses While student presence is a stimulus the greetings are responses Option D A component of Mr Pattersons behavioral repertoire is true in a general sense as these are behaviors he can perform but response class is the more precise and specific ABA term for a group of topographically different behaviors that serve the same function