This question tests knowledge of the specific controlling variables and reinforcement for different verbal operants as described by BF Skinner Understanding the function of each operant helps determine its primary reinforcer A Generalized Conditioned Reinforcer GCR is a conditioned reinforcer that has been paired with many other reinforcers and can be exchanged for or provides access to many other reinforcers eg praise attention tokens money GCRs are effective across a wide range of situations and motivational states Lets examine the reinforcement for each operant Tacts A tact is a verbal operant under the control of a nonverbal discriminative stimulus eg seeing a dog and saying dog Tacting is typically reinforced by a GCR such as praise attention Yes thats a dog or a nod because the reinforcement is not the direct item being named but rather social acknowledgment or confirmation Echoics An echoic is a verbal operant involving repeating what someone else says eg someone says ball and the learner says ball Echoics are typically reinforced by GCRs like praise or attention Good job repeating as the primary function is vocal imitation not to gain access to a specific item Intraverbals An intraverbal is a verbal operant evoked by a verbal discriminative stimulus and does not have pointtopoint correspondence with the verbal stimulus eg Ready set and the learner says Go Intraverbals are also typically reinforced by GCRs such as praise or the continuation of a conversation as the reinforcement is usually social and not directly tied to a specific tangible item Mands A mand is a verbal operant that is a request or a demand under the control of a motivating operation MO and is reinforced by the specific item or event that was requested For example if a child says water because they are thirsty the reinforcement is the water itself not praise or a token While GCRs might be present eg Good asking for water the primary and most direct reinforcer for a mand is the actual item or event that satisfies the MO If the mand does not result in the desired item or action it is unlikely to be strengthened Therefore mands are least likely to be exclusively or primarily reinforced by a GCR in the same way tacts echoics and intraverbals often are because their reinforcement is specific to the motivating operation