In a multi-user operating system, requests for a particular resource arrive at an average rate of 20 per hour (a Poisson arrival process). What is the probability that no request is made in a 45-minute interval?

1. A(A) e^(-15)
2. B(B) e^(-5)
3. C(C) 1 - e^(-5)
4. D(D) 1 - e^(-10)

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