Four of the Most Widely Used Waiting Line Models-M/M/1 or A,M/M/S

Four of the most widely used waiting line models-M/M/1 or A,M/M/S or B,M/D/1 or C,and Limited population or D-all share which of the following three characteristics?

A) normal arrivals,FIFO discipline,and normal service times
B) Poisson arrivals,FIFO discipline,and a single-service phase
C) Poisson arrivals,FIFO discipline,and exponential service times
D) Poisson arrivals,no queue discipline,and exponential service times
E) Poisson arrivals,single-server,and FIFO discipline