The correct answer to this open question is the following.
Although there are no options attached, or further references, we can say the following.
The key detail that is missing in the summary is that Phillip decided to pay close attention to Henry's clues so that he would know exactly when to place Henry in his bed.
It is correct to say that Phillip adopted Henry from the humane society. Immediately, Phillip trained Henry to sleep in his own bed. Philip was effective in training Henry because he followed the advice of using consistency with love. But we have to add the important fact that Phillip decided to pay close attention to Henry's clues so that he would know exactly when to place Henry in his bed.
That was an important factor in the learning process because that is how Philip realized what the dog was trying to tell him with its actions, and according to the training manual, mutual understanding between the owner and the pet, is very important.
Each meeting begins with a quote by Thoreau.
"I went to the woods because I wanted to live deliberately. I wanted to live deep and suck out all the marrow of life."
The main action a writer takes when proofreading is fixing errors.