Answer: Critical
Explanation: The paragraph shows a critical tone due to the last two sentences. The beginning was purely informative of the rising popularity of cell phone usage. None of the particulate tones were being used. As the paragraph progresses, the author switches to the stating a negative side to cell phone usage. This being said, melancholy and humorous make no particular sense as an answer, which leaves us with respectful and critical. We can eliminate respectful because although the author was respectful, there was more to it then just that. Hope that helps!
