In relation to looking for the leash, your dog sitting at the front door is a

• A. CMO-S
• B. MO
• C. CMO-T
• D. EO

Answer: (C)

Transitive motivating operation. A CMO-T occurs when a stimulus doesn’t have reinforcing value by itself but alters the value of another stimulus by making it available as a reinforcer. Here, the dog sitting at the front door doesn’t reward directly, but it signals that going outside is possible if the leash is present. The leash then becomes the means to obtain the walk, so the front-door situation increases the reinforcing value of having the leash. The front door thus functions as a transitive MO, making the leash a more desirable target to obtain the walk. Not an EO because this isn’t about the dog’s internal deprivation state, and not a surrogate MO because there’s no pairing with another MO.