Answer: Ben should include A video of Ben giving Corky a treat after he stops barking.
Step-by-step explanation: A supporting claim is any argument that will make it easier to prove the primary claim. Sometimes, this involves making a distinct argument that only helps to prepare an audience. More often, it involves establishing a piece of fact (evidence.)
In this situation, Ben is making a claim that Rewarding the Pooch get's them to behave. He should use evidence of him giving the Pooch a treat to provide proof of this.