In a well-known tabletop role playing game, a roll of a 20-sided die is treated as a "critical success" only if a "20" is rolled. Assuming a fair die, the probability of rolling a critical success on a single roll is 0.05. A player rolls their ZO-sided die eighteen times {n=18] and observes one critical success {k=1}. To calculate the probability of exactly one "critical success" out of eighteen rolls, we should use the _____ probability model. 0 discrete uniform O Poisson O hypergeometric O binomial 0 negative binomial O geometric