Which sentence would be the BEST introductory sentence for this paragraph? A) Every day in the high school classroom is a new challenge because what electronic resources teachers and students have and how they use them are constantly in flux. B) Some teachers are lax in their classroom discipline, while others have an almost militaristic zeal for enforcing rules strictly. C) Almost every student in the high school classroom today has a cell phone or other communication device that they check constantly. D) The development of the new social media application known as “Twitter” has caused a ruckus in the high school classroom.