Which of the following is not an assumption in common queuing mathematical models?

Select one:

a$.$

Arrivals come from an infinite, or very large, population.

b$.$

Service rates follow the normal distribution.

c$.$

The average service rate is faster than the average arrival rate.

d$.$

Arrivals are treated on a first$-$in$,$ first$-$out basis and do not balk or renege.

e$.$

Arrivals are Poisson distributed.