Choose the mathematical sentence that most accurately expresses the information in the problem, and would be most helpful in solving it. In a certain city, there are 17 television stations. Six of the stations are broadcast below channel 20. How many stations are broadcast at or above channel 20? A. t + 6 + 17 B. t + 6 = 20 C. t - 6 = 20 D. t - 6 = 17 E. t + 6 = 17 F. t = 17 + 6