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

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 three characteristics, which are

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, long queue discipline, and multiple service times.