17. Airline overbooking is a common practice. Many people make reservations on several flights due to uncertain plans and then cancel at the last minute or simply fail to show up. Eagle Air is a small commuter airline. Its planes hold only 15 people. Past records indicate that 20% of the people making a reservation do not show up for the flight. Let X denote the number of people making a reservation but do not show up for the flight out of 15 passengers. What of the following condition is not necessary for X to be a binomial random variable? (A) A passenger is considered as a trial. (B) Each trial has only two outcomes such as "show up" and "don't show up". (C) Each trial has the same probability of passenger not showing up. (D) Trials are uncorrelated. (E) Trials are independent.