Christina knows that her monthly cell phone bill depends on the amount of data that she uses. what can you learn by looking at the graph? a) if christina uses 50 mb of data, she will not be charged a cell phone bill for the month. b) christina is charged $20 for every 1,000 mb of data she uses. c) christina is charged $100 for every 2 mb of data she uses. d) if christina uses 80 mb of data, then her monthly bill will be $1,500.