Answer:
I believe the best answer to be indeed letter C) The owner will need to carry fewer and fewer treats, as the dog's training advances.
Explanation:
This list of instructions is teaching readers how to train their dog to walk on a leash. It's not about the dog's docility, since even mild-tempered dogs may get too excited about going for a walk and end up pulling on the leash. The instructions do not say the dog will require shorter walks as training progresses; quite the opposite, longer walks will be necessary and possible. At no one point does the list say anything that may induce us to believe the dog won't need a leash in the future. From the title itself we can grasp that the purpose is to have the dog walk on a leash.
After eliminating letters A, B, and D, we are left with C) The owner will need to carry fewer and fewer treats, as the dog's training advances. According to the instructions, the dog will need to be rewarded very frequently at the beginning of training, as a means to encourage good behavior. As training progresses, however, the dog will be able to walk longer distances without receiving treats. That means, from a logic point of view, that the owner won't have to take as many treats as before, since the dog will be rewarded fewer times.
