A small tow internet service provider receives 12 customer service calls every 24 hours. Suppose the number of customer service calls follows an exponential distribution. What is the probability: A. No calls will occur for at least four (4) hours: B. A call (one) will occur in the next 45 minutes: C. A call will occur in the next one (1) hour: D. A call will be received between two (2) to four (4) hours