Which is one purpose for providing additional resources at the end of an informational text

1.)to prove there are no counterclaims for the facts provided by the author

2.)to make it unnecessary for the reader to do additional research

3.)to show the author established clams by doing credible research

4.)to prove information to the reader on topics unrelated to the text

Buck did not cry out. he did not check himself, but drove in upon spitz, shoulder to shoulder, so hard that he missed the throat. they rolled over and over in the powdery snow. spitz gained his feet almost as though he had not been overthrown, slashing buck down the shoulder and leaping clear. twice his teeth clipped together, like the steel jaws of a trap, as he backed away for better footing, with lean and lifting lips that writhed and snarled. read this passage. explain what the conflict shows about buck and spitz.