Dear Lucky,
I am going to spend a couple of minutes to clarify once again the way to post on the board
According to the rules
rc-forum-rules-must-read-155874.html you must
1) post ALL the questions along the passage and NOT only one
2) provide the OA in spoiler /[spoiler=]OA[spoiler]
3) the passage being crafted in a good manner
Back to your question
you can tackle the tone of the passage thinking, in a more general way, that it is or positive or negative on the GMAT. rarely it is neutral
Moreover, you can infer it from the whole passage. No matter what.
Hope this helps
regards