Based on the sentence "Tommy is a better dog than Sam," the conclusion that can be drawn is limited. The provided sentence does not explicitly support any of the conclusions given:
- Tommy responds to commands. - The sentence does not provide information about how Tommy responds to commands.
- Tommy learns tricks more quickly than other dogs. - The sentence does not imply anything about Tommy's ability to learn tricks.
- Tommy is more reliable than any other dog. - The sentence does not provide any information regarding Tommy's reliability compared to other dogs.
Therefore, the most accurate conclusion from the given options is None of the choices.