I would say C. It is different from the other answers because they involve saving Travis's life in some way, which dogs are rather "programmed" to do for their owners already. When Old Yeller licks the wound on Travis's leg, he is not doing this to save Travis's life. He is doing this because he cares for Travis, and he cares so much that he ignores his own wounds and tries to tend to Travis's wounds. I hope this helps. :)