In a telephone enquiry system, the number of phone calls regarding relevant enquiry follow poisson distribution with an average of five phone calls during 10-minute time intervals. The probability that there is at the most one phone call during a 10-minute time period is
A. `(6)/(5^e)`
B. `(5)/(6)`
C. `(6)/(55)`
D. `(6)/(e^5)`
