The number of telephone calls that arrive at a phone exchange is often modeled as a Poisson random variable. Assume that on the average there are 10 calls per hour. What is the probability that there are exactly 10 calls in 45 mins? What is the probability there are no calls within 45 mins? 0 a, 0.1251, 0.000045 O b_NONE O c. 0.0858, 0.0006 0 d_ 0.8622, 0.0006