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 Finite 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

B